Medical device guidance

ABSTRACT

A system and method for providing image guidance for placement of one or more medical devices at a target location. The system can be used to display portions of a display object, such as a rendered medical image, at different transparency levels. The system can also be used to resolve co-located display objects, such as a co-located image guidance cue and rendered medical image. The system can further be used to adjust a point-of-view location for one or more medical display objects within a virtual 3D space.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. application Ser. No.14/212,933, entitled “Medical Device Guidance,” filed Mar. 14, 2014,which claims priority benefit to U.S. Provisional Application No.61/783,044, entitled “Determining A Perspective View And ProvidingMultiple Copies Of An Ultrasound Slice,” filed Mar. 14, 2013, each ofwhich is hereby incorporated herein by reference in its entirety.

TECHNICAL FIELD

The systems and methods disclosed herein relate generally to computersystems facilitating medical device guidance through tissue by a medicalpractitioner.

BACKGROUND

Various medical device systems are available to aid a healthcareprovider to guide a medical device in a patient. The medical devicesystems can provide various image guidance cues to aid the healthcareprovider, and can also provide views of images of an imaged area and ofvirtual medical devices corresponding to physical medical devices.

Unfortunately, in some instances, the orientation of the view, as wellas a point-of-view location, are fixed and cannot be changed by theuser. In addition, systems that display image guidance elements oftendisplay a translucent medical image so that any guidance elementslocated behind the medical image can be seen. However, by decreasing theopacity (and the image intensity and contrast) of the medical image, itcan be more difficult for the healthcare provider to identify importantfeatures in the medical image. In addition, when image guidance cues areco-located with medical display object on the display, the medicaldevice system may switch between displaying the image guidance cue andthe medical display object, resulting in a flicker.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram of an embodiment of a system for image-guidedmedical procedures.

FIG. 2 is a diagram of an embodiment of a rendering of image guidancecues and medical display objects on a display.

FIG. 3A is a diagram illustrating an embodiment of the relative locationof a display with respect to a patient and a user.

FIG. 3B is a diagram illustrating an embodiment with multiple displaysdisplaying different perspective views of a virtual medical device basedon the pose of the medical device with respect to differentpoint-of-view locations.

FIG. 4 is a flow diagram illustrative of an embodiment of a routineimplemented by the system to configure a point-of-view location.

FIG. 5 is a diagram of an embodiment of rendered image guidance cues andmedical display objects on a display.

FIG. 6A is a flow diagram illustrative of another embodiment of aroutine implemented by the system to resolve co-located display objects.

FIG. 6B is a flow diagram illustrative of an embodiment of a routineimplemented by the system to resolve co-located display objects.

FIG. 7 is a diagram illustrative of an embodiment of two copies of animage and a virtual medical device.

FIG. 8A is a flow diagram illustrative of an embodiment of a routineimplemented by the system to display portions of a display object atdifferent transparency levels.

FIG. 8B is a flow diagram illustrative of another embodiment of aroutine implemented by the system to display portions of a displayobject at different transparency levels.

DETAILED DESCRIPTION

Implementations disclosed herein provide systems, methods and apparatusfor generating images facilitating medical device insertion into tissueby an operator. Certain embodiments pertain to a free-hand medicaldevice guidance system. The system can provide the healthcare providermanual control over the medical device, while making the spatialrelationships between the target, medical device and U/S image moreintuitive via a visual display. Using this visual feedback, the operatorcan adjust the medical device's position, orientation, or trajectory.Certain of the contemplated embodiments can be used in conjunction withsystems described in greater detail in U.S. patent application Ser. No.13/014,587, filed Jan. 26, 2011, entitled SYSTEMS, METHODS, APPARATUSES,AND COMPUTER-READABLE MEDIA FOR IMAGE MANAGEMENT IN IMAGE-GUIDED MEDICALPROCEDURES and U.S. patent application Ser. No. 13/753,274, filed Jan.29, 2013, entitled MULTIPLE MEDICAL DEVICE GUIDANCE (the '274Application), each of which is hereby incorporated by reference in itsentirety.

The system can aid the healthcare provider in guiding one or moremedical devices through the tissue of the patient and/or placing themedical devices, and can be used for treatment of tumors, fibroids orcysts, with bipolar radiofrequency medical device ablation, multiplemicrowave medical devices, electroporation, and/or electrochemotherapysystems. It can also be used for nerve or muscle stimulation or sensing(electrodes in the spine, brain). The system can be used during opensurgery, laparoscopic surgery, endoscopic procedures, biopsies, and/orinterventional radiology procedures.

The system can be used in conjunction with live intraoperativeultrasound (U/S), pre-operative CT, or any cross-sectional medicalimaging modality (e.g. MRI, OCT, etc.). In addition, the system can usea variety of techniques to determine the position and/or orientation ofone or more medical devices. For example, the system can use the NDIAurora magnetic system, NDI Polaris optical system, etc. In someembodiments, a position sensor can be embedded inside, or affixed toeach medical device, at the tip, along the shaft, or on the handle.Sensors can be built into the medical devices or attached aftermanufacturing, as described in greater detail in U.S. application Ser.No. 14/212,184, filed Mar. 14, 2014, entitled SENSOR MOUNT, incorporatedherein in its entirety.

Each medical device can be associated with one or more sensors, whichcontinually report position and/or orientation, or a single sensor canbe used for all the medical devices. In embodiments where one sensor isused, the healthcare provider can attach the sensor to the particularmedical device that she is intentionally repositioning, and then, onceshe has placed that medical device, she would remove the sensor andattach it to the next medical device she is repositioning. In someembodiments, the medical devices, U/S probe and/or laparoscope can bemanipulated by the healthcare provider. In certain embodiments, thesystem can be used with a robotic manipulator, where the robot controlsthe medical devices, U/S probe and/or laparoscope.

In some embodiments, the handles of medical devices can have push-buttonswitches, to allow the user to select a medical device, indicate atissue target, etc. The handle can also have an indicator light toindicate to the users which medical device is selected. Finally, thehandle can have an encoder to detect how much length of electrode hasbeen exposed by the user, and report this information to the guidancesystem and therapeutic generator

Image Guidance Systems

FIG. 1 is a diagram illustrating an embodiment of a system for imagemanagement in image-guided medical procedures. In some embodiments, theposition sensing unit 140 can track surgical instruments, also referredto herein as medical devices, within a tracking area and provide data tothe image guidance unit 130. The medical devices can include invasivemedical devices, biopsy needles, ablation needles, surgical needles,nerve-block needles, or other needles, electrocautery device, catheters,stents, laparoscopic cameras, or other instruments that enter a part ofthe body, and non-invasive medical devices that do not enter the body,such as ultrasound transducers. The medical devices can also includemedical imaging devices that provide or aid in the selection of medicalimages for display. In some embodiments, the medical imaging device canbe any device that is used to select a particular medical image fordisplay. The medical imaging devices can include invasive medicaldevices, such as laparoscopic cameras, and non-invasive medical devices,such as ultrasound transducers.

Although only two surgical instruments 145 and 155 are shown in FIG. 1,it will be understood that additional surgical instruments can betracked and associated data can be provided to the image guidance unit130. The image guidance unit 130 can process or combine the data andshow image guidance data on display 120. This image guidance data can beused by a healthcare provider to guide a procedure and improve care.There are numerous other possible embodiments of system 100. Forexample, many of the depicted modules can be joined together to form asingle module and can be implemented in a single computer or machine.Further, additional position sensing units can be used in conjunctionwith position sensing unit 140 to track all relevant surgicalinstruments 145 and 155, as discussed in more detail below. Additionalimaging units 150 can be included, and combined imaging data from themultiple imaging units 150 can be processed by image guidance unit 130and shown on display unit 120. Additionally, two or more surgicalsystems 149 can also be included.

Information about and from multiple surgical systems 149 and attachedsurgical instruments 145 (and additional surgical instruments not shown)can be processed by image guidance unit 130 and shown on display 120.These and other possible embodiments are discussed in more detail below.

Imaging unit 150 can be coupled to image guidance unit 130. In someembodiments, imaging unit 150 can be coupled to a second display unit(not shown). The second display unit can display imaging data fromimaging unit 150. The imaging data displayed on display unit 120 anddisplayed on second display unit can be the same or different. In someembodiments, the imaging unit 150 is an ultrasound machine 150, themovable imaging device 155 is an ultrasound transducer 155 or ultrasoundprobe 155, and the second display unit is a display associated with theultrasound machine 150 that displays the ultrasound images from theultrasound machine 150. In some embodiments, a movable imaging unit 155can be connected to image guidance unit 130. The movable imaging unit155 can be useful for allowing a user to indicate what portions of afirst set of imaging data are to be displayed. For example, the movableimaging unit 155 can be an ultrasound transducer 155, a needle or othermedical device, for example, and can be used by a user to indicate whatportions of imaging data, such as a pre-operative CT scan, to show on adisplay unit 120 as image 125. Further, in some embodiments, there canbe a third set of pre-operative imaging data that can be displayed withthe first set of imaging data.

In some embodiments, system 100 comprises a display unit 120 and aposition sensing unit 140 communicatively coupled to image guidance unit130. In some embodiments, position sensing unit 140, display unit 120,and image guidance unit 130 are coupled to the stand 170. Image guidanceunit 130 can be used to produce images 125 that are displayed on displayunit 120. The images 125 produced on display unit 120 by the imageguidance unit 130 can be determined based on ultrasound or other visualimages from the first surgical instrument 145 and second surgicalinstrument 155.

For example, if the first surgical instrument 145 is an ablation needle145 and the second surgical instrument 155 is an ultrasound probe 155,then images 125 produced on display 120 can include the images, orvideo, from the ultrasound probe 155 combined with other medical displayobjects and image guidance cues, such as projected medical device drive(e.g., trajectory indicators) or projected ablation volume (e.g.,ablation zone indicators), determined based on the emplacement ofablation needle 145. If the first surgical instrument 145 is anultrasound probe 145 and the second surgical instrument 155 is alaparoscopic camera 155, then images 125 produced on display 120 caninclude the video from the laparoscopic camera 155 combined withultrasound data superimposed on the laparoscopic image. More surgicalinstruments can be added to the system. For example, the system caninclude an ultrasound probe, ablation needle, laparoscopic camera,stapler, cauterizer, scalpel and/or any other surgical instrument ormedical device. The system can also process and/or display collecteddata, such as preoperative CT scans, X-Rays, MRIs, laser scanned 3Dsurfaces etc.

The term “emplacement” and the term “pose” as used herein are broadterms encompassing their plain and ordinary meanings and may refer to,without limitation, position and/or orientation, the combination ofposition and orientation, or any other appropriate location information.In some embodiments, the imaging data obtained from one or both ofsurgical instruments 145 and 155 can include other modalities such as aCT scan, MRI, open-magnet MRI, optical coherence tomography (“OCT”),positron emission tomography (“PET”) scans, fluoroscopy, ultrasound, orother preoperative, or intraoperative 2D or 3D anatomical imaging data.In some embodiments, surgical instruments 145 and 155 can also bescalpels, implantable hardware, or any other device used in surgery. Anyappropriate surgical system 149 or imaging unit 150 can be attached tothe corresponding medical instruments 145 and 155.

As noted above, images 125 produced can also be generated based on live,intraoperative, or real-time data obtained using the second surgicalinstrument 155, which is coupled to second imaging unit 150. The term“real time” as used herein is a broad term and has its ordinary andcustomary meaning, including without limitation instantaneously ornearly instantaneously. The use of the term real time can also mean thatactions are performed or data is obtained with the intention to be usedimmediately, upon the next cycle of a system or control loop, or anyother appropriate meaning. Additionally, as used herein, real-time datacan be data that is obtained at a frequency that would allow ahealthcare provider to meaningfully interact with the data duringsurgery. For example, in some embodiments, real-time data can be amedical image of a patient that is updated one time per second. In someembodiments, real-time data can be ultrasound data that is updatedmultiple times per second.

The surgical instruments 145, 155 can be communicatively coupled to theposition sensing unit 140 (e.g., sensors embedded or coupled to thesurgical instruments 145, 155 can be communicatively coupled with theposition sensing unit 140). The position sensing unit 140 can be part ofimaging unit 150 or it can be separate. The position sensing unit 140can be used to determine the emplacement of first surgical instrument145 and/or the second surgical instrument 155. In some embodiments, theposition sensing unit 140 can include a magnetic tracker and/or one ormore magnetic coils can be coupled to surgical instruments 145 and/or155. In some embodiments, the position sensing unit 140 can include anoptical tracker and/or one or more visually-detectable fiducials can becoupled to surgical instruments 145 and/or 155. In some embodiments, theposition sensing unit 140 can be located below the patient. In suchembodiments, the position sensing unit 140 can be located on or belowthe table 180. For example, in embodiments where the position sensingunit 140 is a magnetic tracker, it can be mounted below the surgicaltable 180. Such an arrangement can be useful when the tracking volume ofthe position sensing unit 140 is dependent on the location of theposition sensing unit, as with many magnetic trackers. In someembodiments, magnetic tracking coils can be mounted in or on the medicaldevices 145 and 155.

In some embodiments, the position sensing unit 140 can be anelectromagnetic measurement system (e.g., NDI Aurora system) usingsensor coils for tracking units attached to the first and/or secondsurgical devices 145 and 155. In some embodiments, the second positionsensing unit 140 can be an optical 3D tracking system using fiducials.Such optical 3D tracking systems can include the NDI Polaris Spectra,Vicra, Certus, PhaseSpace IMPULSE, Vicon MX, InterSense IS-900,NaturalPoint OptiTrack, Polhemus FastTrak, IsoTrak, or ClaronMicronTracker2. In some embodiments, the position sensing unit 140 caneach be an inertial 3D tracking system comprising a compass,accelerometer, tilt sensor and/or gyro, such as the InterSenseInertiaCube or the Nintendo Wii controller. In some embodiments, theposition sensing unit 140 can be attached to or affixed on thecorresponding surgical device 145 and 155.

In some embodiments, the position sensing units 140, can include sensingdevices such as the HiBall tracking system, a GPS device, or signalemitting device that would allow for tracking of the position and/ororientation (e.g., pose) of the tracking unit (also referred to as apose sensor). In some embodiments, a position sensing unit 140 can beaffixed to either or both of the surgical devices 145 and 155. Thesurgical devices 145 or 155 can be tracked by the position sensing unit140. A room coordinate system reference, such as the display 120 canalso be tracked by the position sensing unit 140 in order to determinethe emplacements of the surgical devices 145 and 155 with respect to theroom coordinate system. Devices 145 and 155 can also include or havecoupled thereto one or more accelerometers, which can be used toestimate movement, position, and location of the devices.

In some embodiments, the position sensing unit 140 can be an AscensionFlock of Birds, Nest of Birds, driveBAY, medSAFE, trakSTAR, miniBIRD,MotionSTAR, pciBIRD, or Calypso 2D Localization System and trackingunits attached to the first and/or second medical devices 145 and 155can be magnetic tracking coils.

The term “tracking unit” (also referred to as a pose sensor), as usedherein, is a broad term encompassing its plain and ordinary meaning andincludes without limitation all types of magnetic coils or othermagnetic field sensing devices for use with magnetic trackers, fiducialsor other optically detectable markers for use with optical trackers,such as those discussed above and below. In some embodiments, thetracking units can be implemented using optical position sensingdevices, such as the HiBall tracking system and the position sensingunit 140 can form part of the HiBall tracking system. Tracking units canalso include a GPS device or signal emitting device that allows fortracking of the position and/or orientation of the tracking unit. Insome embodiments, a signal emitting device might include aradio-frequency identifier (RFID). In such embodiments, the positionsensing unit 140 can use the GPS coordinates of the tracking units orcan, for example, triangulate the radio frequency signal being emittedby the RFID associated with tracking units. The tracking systems canalso include one or more 3D mice.

Images 125 can be produced based on intraoperative or real-time dataobtained using first surgical instrument 145, which is coupled to firstsurgical system 149. In the illustrated embodiment of FIG. 1, the firstsurgical system 149 is shown as coupled to image guidance unit 130. Thecoupling between the first surgical system 149 and image guidance unit130 may not be present in all embodiments. In some embodiments, thecoupling between first surgical system 149 and image guidance unit 130can be included where information about first surgical instrument 145available to first surgical system 149 is useful for the processingperformed by image guidance unit 130. For example, in some embodiments,the first surgical instrument 145 is an ablation needle 145 and firstsurgical system 149 is an ablation system 149. In some embodiments, itcan be useful to send a signal about the relative strength of plannedablation from ablation system 149 to image guidance unit 130 in orderthat image guidance unit 130 can show a predicted ablation volume. Inother embodiments, the first surgical system 149 is not coupled to imageguidance unit 130. Example embodiments including images and graphicsthat can be displayed are included below.

In some embodiments, the display unit 120 displays 3D images to a user,such as a healthcare provider. Stereoscopic 3D displays separate theimagery shown to each of the user's eyes. This can be accomplished by astereoscopic display, a lenticular auto-stereoscopic display, or anyother appropriate type of display. The display 120 can be an alternatingrow or alternating column display. Example alternating row displaysinclude the Miracube G240S, as well as Zalman Trimon Monitors.Alternating column displays include devices manufactured by Sharp, aswell as many “auto-stereoscopic” displays (e.g., Philips). In someembodiments, Sony Panasonic 3D passive displays and LG, Samsung, and/orVizio 3D TVs can be used as well. Display 120 can also be a cathode raytube. Cathode Ray Tube (CRT) based devices, can use temporal sequencing,showing imagery for the left and right eye in temporal sequentialalternation. This method can also be used projection-based devices, aswell as by liquid crystal display (LCD) devices, light emitting diode(LED) devices, and/or organic LED (OLED) devices.

In certain embodiments, a user can wear a head mounted display in orderto receive 3D images from the image guidance unit 130. In suchembodiments, a separate display, such as the pictured display unit 120,can be omitted. The 3D graphics can be produced using underlying datamodels, stored in the image guidance unit 130 and projected onto one ormore 2D planes in order to create left and right eye images for a headmount, lenticular, or other 3D display. The underlying 3D model can beupdated based on the relative emplacements of the various devices 145and 155, as determined by the position sensing unit(s), and/or based onnew data associated with the devices 145 and 155. For example, if thesecond medical device 155 is an ultrasound probe, then the underlyingdata model can be updated to reflect the most recent ultrasound image.If the first medical device 145 is an ablation needle, then theunderlying model can be updated to reflect any changes related to theneedle, such as power or duration information. Any appropriate 3Dgraphics processing can be used for rendering including processing basedon OpenGL, Direct3D, Java 3D, etc. Whole, partial, or modified 3Dgraphics packages can also be used, such packages including 3DS Max,SolidWorks, Maya, Form Z, Cybermotion 3D, VTK, Slicer, or any others. Insome embodiments, various parts of the needed rendering can occur ontraditional or specialized graphics hardware. The rendering can alsooccur on the general CPU, on programmable hardware, on a separateprocessor, be distributed over multiple processors, over multiplededicated graphics cards, or using any other appropriate combination ofhardware or technique.

One or more modules, units, devices, or elements of various embodimentscan be packaged and/or distributed as part of a kit. For example, in oneembodiment, an ablation needle, one or more tracking units, 3D viewingglasses, and/or a portion of an ultrasound wand can form a kit. Otherembodiments can have different elements or combinations of elementsgrouped and/or packaged together. Kits can be sold or distributedseparately from or with the other portions of the system.

One will readily recognize that there are numerous other examples ofimage guidance systems which can use, incorporate, support, or providefor the techniques, methods, processes, and systems described herein.

Depicting Surgical Instruments

It can often be difficult to discern the content of a 3D scene from a 2Ddepiction of it, or even from a 3D depiction of it. Therefore, variousembodiments herein provide image guidance that can help the healthcareprovider better understand the scene, relative emplacements or poses ofobject in the scene and thereby provide improved image guidance.

FIG. 2 illustrates a perspective view of a virtual rendering 202 of asurgical instrument 242 being displayed on a screen 220 with aperspective view of a medical image 204. In this case, the renderedsurgical instrument 202 displayed is an ablation needle 242. A wire 246connecting the ablation needle 242 to an ablation system is alsodepicted. Although only one virtual surgical instrument 202 isdisplayed, it will be understood that multiple medical devices can betracked and displayed simultaneously on screen 220, as described ingreater detail in the '274 Application, previously incorporated byreference. For example, a virtual rendering of the medical imagingdevice that corresponds to the medical image 204 can be displayed.

The virtual surgical instrument 202 can be displayed in a virtual 3Dspace with the screen 220 acting as a window into the virtual 3D space.Thus, as the surgical instrument 242 is moved to the right with respectto a point-of-view location (e.g., the location of the point-of-view forviewing the 3D space), the virtual surgical instrument 202 also moves tothe right. Similarly, if the surgical instrument 242 is rotated 90degrees so that the tip of the surgical instrument is pointing away fromthe point-of-view location (e.g., at the screen 220), the virtualsurgical instrument 201 will likewise show the change in orientation,and show the tip of the virtual surgical instrument 202 in thebackground and the other end of the virtual surgical instrument 202 inthe foreground.

Some models of medical devices have markings such as bands around theshaft (to indicate distance along the shaft), and a colored region 203near the tip to indicate from where the radio frequency or microwaveenergy is emitted in the case of an ablation probe. Healthcare providersperforming medical device procedures are often familiar with thesemarkings and can use them to help understand the spatial relationshipbetween the medical device and anatomy. In some embodiments, the makeand model of the medical device 242 is known to the image guidancesystem and the virtual medical device displayed (202) in display 220 canresemble medical device 242. The features of medical devices that can berendered in the scene include the overall shape (diameter, crosssectional shape, curvature, etc.), color, distance markers, visuals orechogenic fiduciary markers, the state of deployable elements such astines, paddles, anchors, resection loops, stiffening or steerablesleeves, temperature, radiation, light or magnetic field sensors, lens,waveguides, fluid transfer channels, and the like.

The type of medical device being used can be input into the imageguidance system 100, can be a system default, can be detected by acamera or other device, can be received as data from an attached medicaldevice, such as surgical system 149 in FIG. 1, or the information can bereceived in any other appropriate manner. Displaying on display 220, avirtual surgical instrument that resembled the surgical instrument 242can help healthcare providers associate the image guidance data with thereal world and can provide more familiar guidance information to ahealthcare provider, thereby further aiding the healthcare provider inthe guidance task. For example, the healthcare provider can see thefamiliar markings on the medical device being displayed on the display220 and therefore be familiar with the distance and relative placementof the displayed medical device with respect to other data, such as atumor 212 seen in a rendered ultrasound image 204, 205. This knowledgeof relative placement of items being displayed can help the healthcareprovider move the medical device into place.

Consider an embodiment in which the virtual surgical instrument 202 inthe display 220 is an ablation needle depicting the portion of theneedle that will perform the ablation, for example, the portion thatemits the radio or microwave energy. If the display 220 also includesultrasound data, then the doctor can be able to find the tumor 212 shewishes to ablate by moving the ultrasound probe around until she spotsthe tumor 212. In various embodiments, she will be able to see thedisplayed ultrasound data and its location relative to the displayedmedical device with the markings. She can then drive the medical deviceuntil she sees, on display 220, that the emitter-portion of the medicaldevice encompasses the tumor in the ultrasound, also seen on display220. When she activates the ablation, she can then be much more certainthat she has ablated the correct portion of the tissue. Variousembodiments of this are discussed below.

As another example, consider the physical markings that can be on theinstruments themselves. These markings can help orient a healthcareprovider during use of the instrument. In some embodiments, the imageguidance unit can represent these markings in the images displayed inthe display. For example, certain ultrasound transducers are built withan orientation mark (e.g., a small bump) on one side of the transducingarray. That mark can also be shown in the ultrasound image on thescanner's display, to help the healthcare provider understand where thescanned anatomical structures shown on screen are located under thetransducer, inside the patient. In some embodiments, the image guidancesystem can display a symbolic 3D representation of the orientation markboth next to the motion-tracked ultrasound slice (e.g., moving with thedisplayed ultrasound slice) and next to the 2D ultrasound slice alsodisplayed by the system. An example of this is displayed in FIG. 2,where a small rectilinear volume 214 corresponding to a feature on anultrasound probe is shown both in proximity to the ultrasound slicedisplayed in 3D and the ultrasound slice displayed as a 2D image.

Other embodiments can track and display other types of instruments andtheir features. For example, a healthcare provider may want to track oneor more of a scalpel, a biopsy, a cauterizer (including anelectrocauterizer and Bovies), forceps, cutting loops on hysteroscopes,harmonic sheers, lasers (including CO₂ lasers), etc. For example, invarious embodiments, the following devices can be tracked and variousaspects of their design displayed on display 220: Olympus™ OES ProHystero-Resectoscope, SonoSurg Ultrasonic Surgical System Olympus™ GF-UC160 Endoscope Wallus™ Embryo Transfer Catheter AngioDynamics®NanoKnife™, VenaCure™ laser, StarBurst, Uniblade, Habib® Resector Bovie™Electrodes, Covidien Evident™, Cool-tip™ Ablation Antennas, Opti4™Electrodes Microsulis MEA (microwave endometrial ablation), AcculisHalt™ Medical System Optimed BigLumen Aspiration Catheter OptimedOptipure Stent Central venous catheterization introducer medical device(such as those made by Bard and Arrow).

Once tracked, a healthcare provider is able to see image guidance dataon display 220 that will allow her to know the relative pose, location,or emplacement of the tracked instrument(s) with respect to one anotheror with respect to imaging data and will be able to see, on display 220,the features of the instrument rendered in the scene.

Depicting Ablation Volume and Other Information

Various embodiments of the system can depict information related to thesurgical instruments, such as image guidance cues, as part of the imageguidance data. For example, in some embodiments, an image guidance cuedisplayed by the image guidance system can include an expected sphericalablation volume. For example, FIG. 2 shows a virtual ablation needle 202which has a darkened portion 203 that indicates where the radiofrequency or microwave energy for ablation will be emitted. In someembodiments, an image guidance system can display on display 220 theexpected ablation volume 206. The ablation volume 206 can be shown as atransparent volume, a wireframe volume (as depicted in FIG. 2), as apoint cloud of various densities, as an outline, as a volume, or in anyother appropriate manner. Although only one ablation volume 206 isdisplayed, it will be understood that multiple ablation volumes can bedisplayed for each medical device 242 that is displayed on the screen220.

For some ablation needles, the expected volume of ablated tissue isneither spherical nor centered at the tip of the medical device. Forexample, a Covidien surgical microwave medical device has an ellipsoidalablation volume; a Covidien Evident transcutaneous microwave medicaldevice has a teardrop-like ablation volume; RFA Medical's bipolarablation system uses two medical devices simultaneously, where eachmedical device has paddles that deploy after the medical device isinserted inside the tissue (which one can equate to a canoe's oar). Insome embodiments, the ablation volume for such a medical device is, to afirst approximation, a volume that lies directly between the paddles ofthe two medical devices.

The pose of the volume can be specified by the placement of a trackedmedical device, such as medical device 242 in FIG. 2. In someembodiments, with single medical device ablation systems, the volume'sapproximate size (e.g., girth and length, if ellipsoidal) can be eitherspecified by the healthcare provider, or automatically computed by theguidance system. The ablation volume 206 can be based on numerousparameters such as the medical device make and model, power and durationsettings of the microwave or radio frequency generator, measured orestimated temperature and impedance of the target tissue or other tissueinformation, a formula, a look-up-table, fixed or default values, orbased on any other appropriate available information.

Other instrument information can also be depicted. For example, if acauterizer is tracked as part of an image guidance system, then thecauterization volume can be determined or estimated and that volume canbe displayed. If a laser is tracked as part of the image guidancesystem, then the projected laser path can be determined or estimated anddisplayed. In embodiments where multiple medical devices are used, thecombined volume can be shown, as described in greater detail in the '274Application.

Depicting Medical Device Placement, Trajectory, and Other Image GuidanceCues

In certain procedures, the system can provide image predictioninformation related to the surgical instruments as image guidance cues.In the context of scalpel movement, this can be the location that thescalpel will hit if a healthcare provider continues to move the scalpelin a particular direction. In the context of ablation or biopsies, thiscan be the projected medical device placement if it is driven along itscentral axis, which is also referred to herein as a longitudinal axis.

FIG. 2 further illustrates an embodiment of a projected needle drive 208(also referred to as a trajectory indicator) as an image guidance cue.If a healthcare provider is driving an ablation needle 242 into tissue(not pictured), then she can know where the medical device will bedriven. In some embodiments, the projected drive 208 of a medical devicecan be depicted on the display 220 and can show the healthcare providerthe projected path 208 that the medical device 242 will take if it isdriven along its central axis. Although the trajectory of only onemedical device is displayed, it will be understood that the trajectoryof multiple medical devices can be determined and displayedsimultaneously on screen 220, as described in greater detail in the '274Application.

In some embodiments, to implement the trajectory indicators 208, theimage guidance system can draw a number of rings about the axis of themedical device shaft, extrapolated beyond its tip, as depicted in FIG.4. A healthcare provider can view and manipulate the pose of the medicaldevice 242 and its expected drive projection (via its displayedprojected trajectory) before it enters the patient's tissue. In someembodiments, this is accomplished by the doctor positioning the virtualrings in the drive projection such that they are co-incident (or passthrough) the ultrasound representation of a target, such as a tumor thatthe doctor has spotted in the ultrasound. This can allow the healthcareprovider to verify that the medical device 242 is properly aimed at thetarget and can drive the medical device 242 forward into the tissue suchthat it reaches its desired target or destination. For example, if thedoctor identifies a tumor 212 in the ultrasound image, she can align theablation needle 242 such that the drive projection rings on display 220intersect or otherwise indicate that the medical device, if drivenstraight, will reach the tumor 212.

The rings can be spaced at regular (e.g., 0.5, 1, or 2 cm) intervals toprovide the healthcare provider with visual or guidance cues regardingthe distance from the medical device tip to the targeted anatomy. Insome embodiments, the spacing of the rings can indicate other aspects ofthe data, such as the drive speed of the medical device, the density ofthe tissue, the distance to a landmark, such as the ultrasound data, orany other appropriate guidance data or property. In some embodiments,the rings or other trajectory indicators can extend beyond the medicaldevice tip, by a distance equal to the length of the medicaldevice-shaft. This way, the user knows if the medical device is longenough to reach the target—even before the tip enters the patient. Thatis, in some embodiments, if the rings do not reach the target with thetip still outside the body, then the tip won't reach the target evenwhen the entire length shaft is inserted into the body.

Other display markers can be used to show trajectory, such as a dashed,dotted, or solid line, transparent medical device shaft, point cloud,wire frame, etc. In some embodiments, three-dimensional rings can beused and provide depth cues and obscure little of the ultrasound image.Virtual rings or other virtual markers can be displayedsemi-transparently, so that they obscure less of the ultrasound imagethan an opaque marker would.

Other prediction information can also be displayed as image guidancecues. For example, if a scalpel is being tracked by the image guidancesystem, then a cutting plane corresponding to the scalpel can bedisplayed (not pictured). Such a cutting plan can be coplanar with theblade of the scalpel and can project from the blade of the scalpel. Forexample, the projected cutting plane can show where the scalpel wouldcut if the doctor were to advance the scalpel. Similar predictioninformation can be estimable or determinable for cauterizers, lasers,and numerous other surgical instruments.

Furthermore, the data from two or more devices can be combined anddisplayed based on their relative emplacements or poses. For example,the system 100 can determine an image plane based on the emplacementinformation of the ultrasound probe 222. Further, the renderedultrasound image 204 can be displayed on the image plane with respect tothe virtual medical device 202 on the display 220 in a manner thatestimates the relative emplacements or poses of an ultrasound probe 222and the medical device 242. As illustrated in FIG. 2, the image guidancecues associated with the virtual medical 202, including the ablationvolume indicator 206 and trajectory indicators 208, are shown spatiallylocated with the rendered ultrasound image 204 on display 220.

In addition, the display 220 includes another image guidance cue in theform of an intersection indicator 210 that indicates the where thevirtual ablation medical device 202 intersects the ultrasound image 204.In some embodiments, the intersection indicator 210 can be displayedbefore the medical device is inserted, thereby allowing the healthcareprovider to see where the medical device will intersect the image, orimaged area.

In the illustrated embodiment, a tumor 212 appears in the ultrasoundimage, or rendered ultrasound image 204, and the virtual ablation needle202 is shown driven through the tumor 212. The ablation volume 206estimates where ablation would occur if the tissue were ablated at thattime. The healthcare provider can see that the ablation volume 206appears to cover the tumor displayed in the ultrasound image.

Various embodiments can include any combinations of the graphicsdescribed above and/or other graphics or image guidance cues. Forexample, in some embodiments, data related to a single surgicalinstrument (such as an ablation needle, ultrasound probe, etc.) can bepresented in more than one manner on a single display. Consider anembodiment in which device 242 is an ablation needle and device 222 isan ultrasound transducer. As mentioned previously, as the medicaldevices are displayed in a virtual 3D space, with the screen 220 actingas a window into the virtual 3D space, if a healthcare provider orientsultrasound transducer 222 such that it is perpendicular to thepoint-of-view or point-of-view location (e.g., perpendicular to thescreen), the perspective view of the ultrasound image 204 would showonly the edge and the contents of the ultrasound image 204 would not bevisible. In some embodiments, the image guidance system can track thehealthcare provider's head using a pose sensor and/or a position sensingunit. In some embodiments, such as, when the head of a user is tracked,the healthcare provider can then move her head to the side, so that shesees the ultrasound image from a different point of view location.

In some embodiments, the image guidance system can constantly display anadditional 2D view 205 of the ultrasound image, simultaneous to the 3Ddepiction 204, so that the ultrasound image is always visible,regardless of the pose in which the healthcare provider holds thetransducer 222. The 2D image 205 of the ultrasound data can be similarto what a healthcare provider is accustomed to seeing with traditionalultrasound displays. This can be useful to provide the healthcareprovider with imaging to which she is accustomed and allows a healthcareprovider to see the ultrasound data regardless of the then-current poseof the ultrasound probe with respect to the user.

In some embodiments, the 2D view 205 of an ultrasound image is depictedin the upper right corner of the monitor (though it can be placed in anylocation). In some embodiments, the guidance system can automatically(and continually) choose a corner in which to render the 2D view 205 ofthe ultrasound image, based on the 3D position of the surgicalinstruments in the rendered scene. For example, in FIG. 2, ablationneedle 242 can be held in the healthcare provider's left hand and themedical device shaft is to the left of the 3D ultrasound image slice, sothat the 2D view 202 of the ultrasound image in the upper right cornerof display 220 does not cover any of the 3D features of the medicaldevice (or vice-versa). If the medical device were held in thehealthcare provider's right hand, the virtual medical device shaft wouldappear on the right side. To prevent the 2D view 202 in the corner ofdisplay 220 from covering the medical device shaft, the system canautomatically move it to a corner that would not otherwise be occupiedby graphics or data.

In some embodiments, the system attempts to avoid having the 2D view 202of the ultrasound image quickly moving among corners of the display inorder to avoid overlapping with graphics and data in the display. Forexample, a function f can be used to determine which corner is mostsuitable for the 2D ultrasound image to be drawn in. The inputs to f caninclude the locations, in the screen coordinate system, of the displayedmedical device tip, the corners of the 3D ultrasound image, etc. In someembodiments, f's output for any given point in time is independent off's output in the previous frames, which can cause the ultrasound imageto move among corners of the display rapidly. In some embodiments, theimage guidance system will filter f's output over time. For example, theoutput of a filter g, for any given frame, could be the corner which hasbeen output by f the most number of times over the last n frames,possibly weighting the most recent values for f most heavily. The outputof the filter g can be used to determine in which corner of display 220to display the 2D ultrasound image and the temporal filtering providedby g can allow the 2D view 205 of the ultrasound image display to movemore smoothly among the corners of the display 220.

In some embodiments, other appropriate virtual information and/or imageguidance cues can be overlaid on the 2D view 205 of the ultrasound imageas well as the 3D view 204. Examples include: orientation indicator 214,an indication of the distance between the medical device's tip and thepoint in the plane of the ultrasound image that is closest to themedical device tip; the cross section or outline of the ablation volumethat intersects with the ultrasound slice; and/or the intersectionpoint, box, outline, etc. between the medical device's axis and theultrasound image plane.

Furthermore, it will be understood that other image guidance cues can begenerated and displayed on the display as described in greater detail inthe '274 Application, previously incorporated herein by reference. Forexample, the system 100 can generate and/or display graphical indicatorsthat help indicate the spatial relationship between a medical device andan ultrasound image plane (e.g., graphical image plane indicators) orother plane (e.g., graphical plane indicators), indicators to indicatethe relative positions of the medical device(s) and ultrasound image,features of interest, annotations, foundational plane indicators,foundational plane intersection indicators, other graphical indicators,approximate medical device location indicators, etc. As described ingreater detail above and in the '274 Application, the various imageguidance cues can be generated based at least in part on the emplacementinformation of the medical devices used with the system 100.

Configuring the Point-of-View Location

FIG. 3A is a diagram illustrating an embodiment of the relative locationof a display 302 with respect to a patient 304 and a user 306. In theillustrated embodiment, the display 302 is located on one side of thepatient 304, and the user 306 is located on an opposite side. However,it will be understood that the display 302 and/or user 306 can belocated in any configuration, as desired. In addition, in theillustrated embodiment, the user 306 is holding a medical device 308 atan angle alpha with respect to an axis of the display 302.

Although not illustrated in FIG. 3A, a pose sensor can be coupled withmedical device 308. Based at least on the emplacement informationreceived from the pose sensor, the system can determine the relativepose of the medical device 308 with respect to the point of viewlocation (which is some distance in front of the display 302 in theillustrated embodiment) and display a perspective view of a virtualmedical device 310 on the display based at least in part on thedetermined relative pose. Although the illustrated embodiment of FIG. 3Ashows only the angle alpha, it will be understood that the medicaldevice can be orientated at any angle with respect to the display and/orthe point-of-view location.

In some embodiments, the user 306 can alter the point-of-view locationof the system. For example, if the user moves the display 302 to thefoot of the patient 304, the user may want to change the point-of-viewlocation to coincide with the new relative pose between the user and thedisplay. As another example the system may have a default point-of-viewlocation that requires the position sensing unit to be orientated in aparticular way with respect to the display and/or the user. As such, theuser may want to alter the point-of-view location based on an actualpose of the position sensing unit with respect to the user and/ordisplay.

To alter or configure the point-of-view location, the user 304 canposition the medical device 308 at a predetermined pose with respect tothe display 302. The predetermined pose can be pre-programmed into thesystem or dynamically selected by the user. For example, in someembodiments, the predetermined pose can be orthogonal or parallel to thedisplay 302.

Once the medical device 308 is oriented in the predetermined pose, theuser 306 can enter a command into the system. The user 306 can enter thecommand in a variety of ways, such as, but not limited to, pressing abutton or pedal, clicking/moving a mouse, touching the display 302,gesturing with the body (hand, foot, head) or medical device, etc.

As part of the configuration process, the system 100 can determine therelative pose of the medical device with respect to a referencelocation. The reference location can refer to the location of theposition sensing unit, such as a magnetic and/or optical tracker, orother type of position sensing device, the location of a portion of theposition sensing unit, and/or a coordinate system of the positionsensing unit. For example, if the position sensing unit is located on orbelow the table and orientated in the same way as the table, thereference location can be the coordinate system of the position sensingunit. For example, the reference location may have an x-axis along thelength of the table 312, a y-axis along the width of the table 312, anda z-axis up and down from the table 312. In some embodiments, thereference location can be a direction, such as a geographic direction(e.g., North, etc.).

Using the relative pose of the medical device 308 with respect to thereference location, as well as the known relative pose of thepredetermined pose with respect to the display, the system can determinethe point-of-view location. For example, with reference to theillustrated embodiment of FIG. 3A, if the predetermined pose is parallelto the display 302, and the system determines that the medical device308 is orientated along the line 314 when the command is entered, thesystem can determine that the position sensing unit is orientated suchthat the length of the position sensing unit (and table 312) is parallelto the screen 302 and the width of the position sensing unit isperpendicular to the screen 302. Furthermore, the system can determinethat the point-of-view location is somewhere along the y-direction ofthe position sensing unit. In some embodiments, the exact location ofthe point-of-view location is estimated based at least in part on anexpected distance of the display 302 from the table 312. In someembodiments, the system can determine the location of the medical device308 with respect to the position sensing unit and use that location asthe point-of-view location. In certain embodiments, the point-of-viewlocation is one, both, or a combination of orientation and a location.

Once the point-of-view location is configured, the system can displayperspective views of the virtual medical device 310 with respect to thepoint-of-view location. For example, as illustrated in FIG. 3A, thesystem can display the virtual medical device 310 at an angle alpha,which represents the angle difference between the medical device 308 andthe point-of-view location.

FIG. 3B is a diagram illustrating an embodiment with multiple displays302, 322 displaying different perspective views of the virtual medicaldevice 310A, 310B based on the pose of the medical device 308 withrespect to different point-of-view locations (or the different displays302, 322) As described in greater detail above, with reference to FIG.3A, the user 306 (or user 326) can configure the different point-of-viewlocations for the different displays 302, 322. For example, the user 306can place the medical device 308 in a predetermined pose with respect tothe display device 302 and then enter the configuration command. Usingthe known pose of the predetermined pose with respect to the displaydevice 302 and the pose of the medical device 308 with respect to theposition sensing unit, the system can determine the point-of-viewlocation for the display device 302.

Similarly, the user 306 (or user 326) can configure the point-of-viewlocation for the second display 322. For example, the user 326 canorient the medical device 308 in the predetermined pose with respect tothe display device 322 and then enter the configuration command. Usingthe known pose of the predetermined pose with respect to the displaydevice 322 and the pose of the medical device 308 with respect to theposition sensing unit, the system can determine the point-of-viewlocation for the display device 322. In this way, each user can see aperspective view of the virtual medical devices 310A, 310B from theirrespective points-of-view. For example, as illustrated, when the medicaldevice 308 is orientated as shown in FIG. 3B, the virtual medical device310A is shown pointing into the display 302 with the handle in theforeground with respect to the tip, while the virtual medical device310B is shown pointing out of the display 322 with the handle in thebackground with respect to the tip. When the user 306 rotates themedical device 308 by angle beta and the medical device 308 is parallel(or approximately parallel) to the display 322, the virtual medicaldevice 310B can appear to be parallel (or approximately parallel) to thedisplay 322, while the virtual medical device 310A can appear angledwith respect to the display 302 (e.g., the handle will be in thebackground with respect to the tip).

It will be understood that the system can perform any or all of thefunctions described herein and in the '274 Application, for one or bothof the displays 302, 322. In this way, the system can display differentperspective views of the virtual medical device based at least in parton the pose of the medical device with respect to differentpoint-of-view locations.

In some embodiments, the system 100 can automatically determine thepoint-of-view location(s) based at least in part on emplacementinformation of the medical device 308, the position sensing unit, andthe one or more sets of one or more displays 302, 322. For example, insome embodiments, the medical device 308, the position sensing unit, andthe display(s) 302, 322 can each include a tracking unit (e.g., posesensor). The emplacement information of the medical device 308, theposition sensing unit, and the display(s) 302, 322 can be communicatedto the position sensing unit. Based on the emplacement information, theposition sensing unit can determine the pose of the position sensingunit with respect to the display and/or the user(s), and also determinethe point-of-view location(s). For example, in some embodiments, thesystem 100 can determine the point-of-view location to be in front ofthe display(s) 302, 322, regardless of the current pose of the medicaldevice 308 and/or the position sensing unit with respect to the displays302, 322.

It will be understood that the system can use additional point-of-viewlocations as desired. In addition, multiple perspective views of thevirtual medical device can be displayed on a single display based ondifferent point-of-view locations. Furthermore, in some embodiments,each point-of-view location includes a right eye/left eye point of viewlocation.

FIG. 4 is a flow diagram illustrative of an embodiment of a routine 400implemented by the system 100 to configure a point-of-view location. Oneskilled in the relevant art will appreciate that the elements outlinedfor routine 400 can be implemented by one or more computingdevices/components that are associated with the system 100, such as theposition sensing unit 140, the image guidance unit 130, surgical system149, and/or imaging unit 150. Accordingly, routine 400 has beenlogically associated as being generally performed by the system 100.However, the following illustrative embodiment should not be construedas limiting.

At block 402, the system 100 receives a configuration command. Theconfiguration command can be implemented in a variety of ways. Forexample, in some embodiments, the configuration command can beimplemented as a button pressed by a user on the keyboard, a mouseclick, touch of the display, hand gesture, head gesture, medical devicegesture, or other gesture with the body, etc.

In some embodiments, prior to receiving the configuration command, themedical device can be orientated according to a predetermined pose. Forexample, a user can orient the medical device so that it is in thepredetermined pose with respect to the display. The predetermined posecan be determined at manufacturing and/or dynamically selected by auser. For example, the predetermined pose can be orthogonal to thedisplay and/or centered (horizontally and/or vertically) with thedisplay. In some embodiments, the predetermined pose can be parallel tothe display, etc.

At block 404, the system 100 determines the pose of a medical devicewith respect to a reference location based at least in part on receivedemplacement information of the medical device. As described previously,the emplacement information can be received from a tracking unit coupledand/or embedded with the medical device.

The reference location can refer to the location of the position sensingunit, such as a magnetic and/or optical tracker, or other type ofposition sensing device, the location of a portion of the positionsensing unit, and/or a coordinate system of the position sensing unit.In some embodiments, the reference location can be a geographicaldirection, such as North, etc.

By determining the pose of the medical device with respect to thereference location, the system 100 can determine a pose relationshipbetween the medical device and the reference location. In someembodiments, the system 100 can determine that the medical device ispointing towards the reference location, away from the referencelocation, is centered (or off to the right or left, in front of, behind)with respect to the reference location, is above/below the referencelocation, etc. For example, the system 100 can determine that themedical device is pointing North, is pointing at or away from theposition sensing unit, is pointing at or away from a portion of theposition sensing unit, is parallel or orthogonal to (or somewhere inbetween) the position sensing unit, is to the left or right, in front ofor behind, above or below, the position sensing unit, etc.

In some embodiments, the system 100 can determine the pose of themedical device with respect to the coordinate system of the positionsensing unit. For example, the system 100 can determine whether themedical device is parallel or orthogonal to an axis of the coordinatesystem, whether the medical device is centered on the coordinate system,near a minimum/maximum of the coordinate system, at the origin of thecoordinate system, and/or can determine the angle of the medical devicewith respect to the axis of the coordinate system. For example, if theposition sensing unit includes an electromagnetic field generator withthe x-axis being the width of the field generator, the y-axis being thelength of the field generator, and the z-axis being up/down, theposition sensing unit can determine the relative pose of the medicaldevice with respect to the x, y, and z axis of the field generator(position and/or orientation).

At block 406, the system 100 determines a point-of-view location basedat least in part on the determined pose of the medical device withrespect to the reference location. The point-of-view location can referto the location from which a virtual 3D space is viewed and can be anylocation as desired. For example, if the display is considered a windowinto the virtual 3D space, the point-of-view location can be thelocation of the window with respect to the objects in the virtual 3Dspace. In some embodiments, the point-of-view location can be anylocation with respect to the display, the medical device, and/or theposition sensing unit. In some embodiments, the point-of-view locationis a fixed location, such as in front of the display, etc.

In some embodiments, using the determined pose of the medical devicewith respect to the reference location, as well as the predeterminedpose, the system 100 can determine the point-of-view location. Forexample, if the predetermined pose is parallel to the display, and themedical device is oriented according to the predetermined pose and isalso parallel to the x-axis of the position sensing unit and orthogonalto the y-axis of the position sensing unit, the system 100 can determinethat the x-axis of the position sensing unit is parallel to the display.In addition, the system 100 can determine that the point-of-viewlocation is located some distance away from the display in they-direction of the position sensing unit's coordinate system.Accordingly, moving the medical device along the x-axis can cause thevirtual medical device to move left or right, moving the medical devicealong the y-axis can cause the virtual medical device to move into orout of the display, and moving the medical device along the z-axis cancause the virtual medical device to move up or down.

Similarly, if the predetermined pose is orthogonal to the display, andthe medical device is oriented according to the predetermined pose andis also parallel to the x-axis of the position sensing unit andorthogonal to the y-axis of the position sensing unit, the system 100can determine that the y-axis of the position sensing unit is parallelto the display, and that the point-of-view location is located somedistance away from the display in the x-direction of the positionsensing unit's coordinate system.

In some embodiments, if the medical device is not orientated accordingto the predetermined pose when the point-of-view location is determined,the point-of-view location may be determined differently. For example,if the desired point-of-view location is somewhere along x-axis, but themedical device is orientated 90 degrees off from the predetermined pose,the system 100 can determine that the point-of-view location issomewhere along y-axis or z-axis, rather than the x-axis. Similarly, adifferent point-of-view location can be determined if the medical deviceis in a different location according to the predetermined pose when thepoint-of-view location is determined. For example, if the desiredpoint-of-view location is directly in front of the display (e.g.,centered with respect to the display), and the medical device is to theleft or right of the display, the system 100 can determine that thepoint-of-view location is to the left or right of the center of thedisplay. However, it will be understood that the predetermined pose caninclude one, both, or any combination of a predetermined orientation anda predetermined location.

At block 408, the system 100 determines a perspective view of a virtualmedical device corresponding to the medical device based at least inpart on the pose of the virtual medical device with respect to thepoint-of-view location. As described in greater detail above, thepoint-of-view location can be used to determine a perspective view ofthe virtual medical device. For example, the relative pose of themedical device with respect to the point-of-view location is used todetermine the perspective view of the virtual medical device.Furthermore, as the pose of the medical device changes with respect tothe point-of-view location, the perspective view of the virtual medicaldevice can change as well.

At block 410, the system 100 causes one or more displays to display theperspective view of the virtual medical device in a virtual 3D space. Asdescribed in greater detail above and in the '274 Application,perspective views of virtual medical devices can be displayed on one ormore displays as desired.

It will be understood that fewer, more, or different blocks can be usedas part of the routine 400. Furthermore, the order of the blocks can bechanged as desired. For example, in some embodiments, the blocks 406 and408 can be performed in parallel and/or the system 100 can omit block402. In certain embodiments, the system 100 can determine apoint-of-view location for each eye of a user. For example, thepoint-of-view location determined in block 406 can refer to a left eyeor right eye (or centered between the two eyes) point-of-view location.The point-of-view location for the other eye (or each eye) can bedetermined by moving the determined point-of-view location by apredetermined amount (e.g., a few inches).

In certain embodiments, the system 100 can determine two point-of-viewlocations for two sets of one more displays. In some embodiments, thetwo sets of one or more displays may be offset by a certain number ofdegrees. For example, the two sets of one or more displays may be onopposite sides of a patient.

To determine, the second point-of-view location, the system 100 canreceive a second configuration command, and then perform block 404 basedat least in part on the pose of the medical device at a current time(e.g., at a second time that is after a first time when the systemperforms block 404 to determine the first point-of-view location). Thesystem 100 can then perform block 406 to determine the secondpoint-of-view location. During operation, the system 100 can use the twopoint-of-view locations to determine perspective views of the medicaldevice(s) for the two sets of one or more displays as desired.

In some embodiments, the routine 400 can further include any one or anycombination of the embodiments described in the '274 Application and/orthe embodiments described herein with reference to FIGS. 6A, 6B, 8A, and8B. For example in some embodiments, the routine 400 can include any oneor any combination of: calculating a perspective view in a virtual 3Dspace of the at least one image based at least in part on theemplacement information of the second medical device with respect to thepoint-of-view location, causing the one or more displays to display theperspective view of the at least one image in the virtual 3D space,calculating a perspective view in the virtual 3D space of a virtualfirst medical device corresponding to the first medical device based atleast in part on the emplacement information of the first medical devicewith respect to the point-of-view location and/or calculating aperspective view in the virtual 3D space of a virtual second medicaldevice corresponding to the second medical device based at least in parton the emplacement information of the second medical device with respectto the point-of-view location, and causing the display device to displaya perspective view of the at least one of the virtual first medicaldevice and the virtual second medical device in the virtual 3D space.Any combination of the aforementioned embodiments can be used asdesired.

Co-Located Display Objects

FIG. 5 is a diagram of an embodiment of rendered display objectsincluding image guidance cues and medical display objects on a display,such as the display 120. The diagram further includes gridlinesindicating a background of a virtual 3D space in which the imageguidance cues and medical display objects are located.

The medical display objects included in the illustrated embodiment caninclude a first virtual medical device 502, a second virtual medicaldevice 504, and a rendered image 506. The image guidance cues includedin the illustrated embodiment can include an intersection indicator 508,trajectory indicators 510 and graphical image plane indicators 512, eachof which are described in greater detail above and/or in the '274Application.

As mentioned previously, in some cases, when two display objects areco-located on a display, the system 100 can change from displaying onedisplay object to the other display object and back, repeatedly. Thisoscillation between the two objects can create a flicker or otherdistortion on the display. In some embodiments, to resolve this issue,the system 100 can display one display object in front of the other. Insome embodiments, the system gives one of the objects priority. Theobject given priority (or the object with a higher priority) can then bedisplayed in front of the other object.

The system can give display objects priority in a number of ways. Forexample, the priority of some objects can be predetermined or can bedynamically determined by the user. For example, the system can have alisting of the priority levels of the different display objects. Forexample, in some embodiments, the medical display objects 502, 504, 506can be given a lower priority level than the image guidance cues, orvice versa. Similarly, different medical device objects can be given ahigher priority level than others. For example, the rendered image 506can be given a lower priority level than the virtual medical devices502, 504, or vice versa. Similarly, different image guidance cues 508,510, 512 can be given higher priority levels than others. For example,the intersection indicator 508 can be given a higher priority level thanthe trajectory indicators 510 and/or the graphical plane indicators 512.Any combination of priority levels can be given to the different displayobjects as desired. Furthermore, the priority levels of the displayobjects can be changed as desired.

The system can cause the one or more displays to display one object(e.g., the object with the higher priority) in front of the other objectin a variety of ways. For example, in some embodiments, the system cancompare the priority levels and display the display object with thehigher priority level in place of, or in front of, the other displayobject. In some embodiments, the display object displayed in front ofthe other can be transparent or translucent such that the display objecton bottom (or behind) can still be seen.

In certain embodiments, the system can alter the location or coordinatesof a display object in order to cause the one or more displays todisplay one object in front of the other. In some embodiments, thesystem can alter the location of the display object with the higher orlower priority such that it is no longer co-located with the otherobject. For example, if a portion of an image guidance cue is co-locatedwith and has a higher priority than a portion of a medical displayobject, the system can move the portion of the image guidance cueforward with respect to the point-of-view location so that the portionof the image guidance cue is in front of the portion of the medicaldisplay object. Similarly, the system can move the medical displayobject backwards or move both the image guidance cue and the medicaldisplay object. It will be understood that the system can move thedisplay objects in any direction and combination as desired. Once one orboth display objects are moved, the system can render the display objectas it normally would. The system can perform a similar process for threeor more co-located display objects.

In some instances, to move the display object, the system can alter thecoordinates of the portion of the display object. In some embodiments,the system can alter one or more bits or registers that indicate thelocation of the image guidance cue. In certain embodiments, the systemmoves the display object so that the movement is imperceptible to auser. For example, a user may not be able to discern if the displayobject is moved by a millimeter, a pixel, one or more bits, etc. In someembodiments, the system moves the display object by one or more bits. Incertain embodiments, the system moves the display object by the smallestallowable increment (e.g., one or more bits, pixels, etc.).

As an example, and not to be construed as limiting, in the illustratedembodiment of FIG. 5, the intersection indicator 508 can be co-locatedwith at least a portion of the rendered image 506. As such, the systemmay oscillate between displaying the portions of the intersectionindicator 508 and portions of the rendered image 506. In someembodiments, to resolve this issue, the system can compare the prioritylevels of the intersection indicator 508 and the rendered image 506 todetermine which display object should be displayed in front of theother. In certain embodiments, the system can determine that when theintersection indicator 508 and the rendered image 506 are co-located,the intersection indicator 508 is to be displayed in front of therendered image 506. Based on the determination, the system can displaythe intersection indicator 508 in front of the rendered image 506. Insome embodiments, the system can move the intersection indicator 508and/or the rendered image 506 so that the system considers theintersection indicator 508 in front of the rendered image 506. Oncemoved, the system can display the intersection indicator 508 in front ofthe rendered image 506.

FIG. 6A is a flow diagram illustrative of an embodiment of a routine 600implemented by the system 100 to resolve co-located display objects. Oneskilled in the relevant art will appreciate that the elements outlinedfor routine 600 can be implemented by one or more computingdevices/components that are associated with the system 100, such as theposition sensing unit 140, the image guidance unit 130, surgical system149, and/or imaging unit 150. Accordingly, routine 600 has beenlogically associated as being generally performed by the system 100.However, the following illustrative embodiment should not be construedas limiting.

At block 602, the system 100 determines pose of a first medical devicebased at least in part on emplacement information of the first medicaldevice. In certain embodiments, the system 100 receives emplacementinformation of one or more medical devices within a predetermined areaand uses that information to determine the pose of the one or moremedical devices. In some embodiments, the medical devices are invasivemedical devices, such as ablation or biopsy needles, catheters, etc. Asdescribed previously, the medical devices, such as needles, can includetips, electrodes, and handles. In certain embodiments, the medicaldevices are non-invasive medical devices. In some embodiments, themedical devices are medical imaging devices, such as ultrasoundtransducers and/or laparoscopic cameras.

As described in greater detail above with reference to FIG. 1, eachmedical device can be associated with a tracking unit that providesemplacement information, such as pose information. As describedpreviously, the tracking units can be coupled with and/or implanted intothe medical devices. Using the emplacement information of the trackingunit and known characteristics of the first medical device, the pose forthe first medical device can be determined. Accordingly, by receivingemplacement information from a tracking unit, the system 100 can alsoreceive and/or determine the pose of the first medical device.

At block 604, the system 100 determines the pose of an imaged area basedat least in part on received emplacement information of a second medicaldevice. As mentioned previously, the system 100 can receive emplacementinformation for any number of medical devices and use that informationto determine the pose of the respective medical devices.

In addition, in some embodiments, the system can use the receivedemplacement information to determine the pose of an imaged area that isassociated with and/or corresponds to a medical device. For example, thesecond medical imaging device can be an ultrasound transducer and cangenerate ultrasound images. Based on the known characteristics of theultrasound transducer, such as the dimensions of its correspondingultrasound slice (e.g., width and depth of ultrasound slice, shape ofultrasound slice, etc.), the system 100 can determine the pose of theimaged area (e.g., the area that is captured by the ultrasoundtransducer and/or covered by the ultrasound slice).

As described in greater detail above with reference to FIG. 1, in someembodiments, the second medical device can be used to select image datafrom a set of image data stored previously. The dimensions of theselected image data (or imaged area) can be selected by the user and/ordetermined at manufacturing. For example, the area of the selected imagedata can be the area that is covered by the last two inches of a distalportion of the second medical device and six inches below the secondmedical device. Based on the known dimensions and location of the imagedarea with respect to the second medical device, the system 100 candetermine the pose of the imaged area based at least in part on theemplacement information of the second medical device.

At block 606, the system 100 receives image data based at least on theemplacement information of the second medical device. In someembodiments, the system 100 receives one or more images from the secondmedical device. For example, the second medical device can be a medicalimaging device, such as an ultrasound transducer and can provide one ormore ultrasound images to the system 100. As described in greater detailabove with reference to FIG. 1, in some embodiments, the second medicaldevice is used to select image data from a set of image data storedpreviously. For example, based on the emplacement of the second medicaldevice, the system can receive images corresponding to a CT scan or MRI.In such embodiments, any device can be used as the second medicaldevice.

At block 608, the system generates one or more image guidance cues. Theimage guidance cues can include, but are not limited to, trajectoryindicators (e.g., medical device and/or needle drive indicators),intersection indicators (e.g., image plane intersection indicators,foundational plane intersection indicators, etc.), ablation zoneindicators, spatial indicators (e.g., relative spatial indicators),graphical indicators (e.g., graphical plane indicators), foundationalplane indicators, approximate medical device location indicators, etc.As described in greater detail above and in the '274 Application, thevarious image guidance cues can be generated based at least in part onthe emplacement information of the medical devices used with the system100.

At block 610, the system determines whether at least a portion of animage guidance cue from the one or more image guidance cues isco-located with at least a portion of a medical display object. Themedical display object can include, but is not limited to, a firstvirtual medical device corresponding to the first virtual medicaldevice, a second virtual medical device corresponding to the secondmedical device medical device, the image, the rendered image, therendered image area, and/or one or more additional medical devices.

In some embodiments, to determine whether the portion of the imageguidance cue and the portion of the medical display object areco-located, the system 100 can compare the coordinates of the portion ofthe image guidance cue with the portion of the medical display object.If the coordinates (e.g., the x, y, z coordinates) match (e.g., areequal) or satisfy a distance threshold, the system can determine thatthe portion of the medical display object and the portion of the imageguidance cue are co-located. In certain embodiments, the system 100 candetermine that the portion of the image guidance cue and the portion ofthe medical display object are co-located if the portion of the imageguidance cue and the portion of the medical display object can be mappedto the same pixel in a video or image output data buffer.

The distance threshold can be a predefined distance, such as one or morebits, one or more pixels, etc. In some embodiments, the distancethreshold can be based at least in part on whether the distance betweenthe coordinates is perceptible to a user, which may be based at least inpart on the size of the display, the size of the display relative to theimage and/or imaged area, and/or the distance between the point-of-viewlocation and the display, etc. For example, in some case the distancethreshold can be smaller for larger displays (or larger display:imageratios) and larger for smaller displays (or smaller display:imageratios), or vice versa. In certain cases, the distance threshold can belarger for larger distances between the point-of-view location and thedisplay and smaller for smaller distances between the point-of-viewlocation and the display, or vice versa. In certain embodiments, thedistance threshold can be different for each coordinate.

In certain embodiments, the system 100 can perform the comparison foreach location of the medical display objects and/or each location of theimage guidance cues. In some cases, the system can determine that theportion of the medical display object and the portion of the imageguidance cue are co-located if the portion of the medical display objectand the portion of the image guidance cue are co-located are level andhave the same depth.

In some embodiments, for each location on the display, the system canquery whether a portion of the medical display object and/or a portionof the image guidance cue have been (or will be) mapped to thatlocation. If the system 100 determines that a portion of the medicaldisplay object and a portion of the image guidance cue have been (orwill be) mapped to that location, the system 100 can determine that theportion of the medical display object and the portion of the imageguidance cue are co-located.

At block 612, the system 100 causes the one or more displays to displayone of the portion of the image guidance cue and the portion of thedisplay object in front of the other of the one of the portion of theimage guidance cue and the portion of the medical display object. Insome embodiments, the system 100 does this based at least in part on adetermination that the portion of the image guidance cue is co-locatedwith the portion of the medical display object.

To cause the one or more displays to display the portion of the imageguidance cue or the portion of the display object in front of the other,the system 100 can overlay one portion on top of the other. In someembodiments, the system 100 overlays one portion on top of the othersuch that the portion on bottom cannot be seen (e.g., the portion on topis opaque). In certain embodiments, the system 100 causes the one ormore displays to display the portion on top semi-transparently or moretransparently than the portion on bottom (e.g., at a transparency levelthat is greater than the transparency level of the portion on bottom,etc.).

In certain embodiments, to cause the one or more displays to display theportion of the image guidance cue or the portion of the display objectin front of the other, the system 100 can move one of the portions withrespect to the other. In some embodiments, the system 100 can move theportion of the image guidance cue so that it is no longer co-locatedwith the portion of the medical display object, or vice versa. Forexample, the system 100 can alter the depth (e.g., z coordinate withreference to the display coordinate system) of the portion of the imageguidance cue so that it is in front of or behind the portion of themedical display object, or vice versa. However, it will be understoodthat the system 100 can alter any coordinate of the portion of the imageguidance cue and/or the portion of the medical display object.

Furthermore, the system 100 can move the portion by any amount asdesired. In some embodiments, the system 100 can move the portion by arelatively small increment, such as, for example, by one or more bits(the bits representing the depth, or other coordinate, of the portion).In certain embodiments, the system 100 moves the portion by the smallestavailable increment. For example, the system can move the portion by asingle bit. By moving the one portion relative to the other portion, thesystem 100 can more easily determine how to display the differentportions. For example, the system 100 can determine that one portion isin front of the other portion.

It will be understood that the order of the blocks can be changed asdesired. For example, in some embodiments, the blocks 602 and 604 can beperformed in parallel. In addition, the system 100 can perform similarroutines for any number of display objects (e.g., one or image guidancecues and/or one or more medical display objects) as desired.

Furthermore, it will be understood that fewer, more, or different blockscan be used as part of the routine 600. For example, in someembodiments, the system 100 can omit block 606. In certain embodiments,the system 100 can cause the one or more displays to display the imageguidance cues, determine and cause the one or more displays to displayperspective views of the medical display objects. As part of determiningthe perspective views, the system 100, in some embodiments, candetermine and cause to be displayed a perspective view of the portion ofthe image guidance cue and/or the portion of the first medical deviceobject, as desired.

FIG. 6B is a flow diagram illustrative of an embodiment of a routine 650implemented by the system 100 to resolve co-located display objects. Oneskilled in the relevant art will appreciate that the elements outlinedfor routine 650 can be implemented by one or more computingdevices/components that are associated with the system 100, such as theposition sensing unit 140, the image guidance unit 40, surgical system149, and/or imaging unit 150. Accordingly, routine 650 has beenlogically associated as being generally performed by the system 100.However, the following illustrative embodiment should not be construedas limiting.

At block 652, the system 100 determines a location of a first displayobject. As mentioned previously, the display object can include, but isnot limited to medical display objects (e.g., virtual medical device,rendered image, etc.) and/or image guidance cues (trajectory indicators,intersection indicators, graphical plane indicators, etc.). To determinethe location of the first display object, the system can determine wherethe display object is, or would be, located on a display. For example,the system 100 can refer to a video or image output buffer to determinethe location of the first display object. Furthermore, the location caninclude one or more 2D or 3D coordinates as desired. For example, thefirst display object can have a volume associated with it based on the2D or 3D coordinates. In some embodiments, the location of the displayobject is based at least in part on the pose of a physical medicaldevice.

At block 654, the system 100 can determine a location of a seconddisplay object. The second display object can be a display object thatis different from the first display object. For example, if the firstdisplay object is a virtual medical device and/or a graphical planeindicator, the second display object can be a rendered image, etc.). Thelocation of the second display object can be determined in the same wayas the location of the first display object.

At block 656, the system can determine whether at least a portion of thefirst display object is co-located with at least a portion of the seconddisplay object. In some embodiments, to determine whether the portion ofthe first display object is co-located with the portion of the seconddisplay object, the system 100 can compare the coordinates of theportion of the first display object with the coordinates of the portionof the second display object (e.g., in the video or image outputbuffer). If the coordinates (e.g., the x, y, z coordinates) match (e.g.,are equal) or satisfy a distance threshold, the system can determinethat the portion of the first display object is co-located with theportion of the second display object.

In certain embodiments, the system 100 can perform the comparison foreach location of the medical display objects and/or each location of theimage guidance cues. In some cases, the system can determine that theportion of the first display object is co-located with the portion ofthe second display object if the portion of the first display object islevel with and has the same depth as the portion of the second displayobject. In some embodiments, for each location on the display, thesystem can query whether a portion of the first display object and/or aportion of the second display object have been mapped to that location.If the system 100 determines that a portion of the first display objectand a portion of the second display object have been mapped to thatlocation, the system 100 can determine that the portion of the medicaldisplay object and the portion of the image guidance cue are co-located.

At block 658, the system 100 causes the one or more displays to displayone of the portion of the first display object and the portion of thesecond display object in front of the other of the one of the portion ofthe first display object and the portion of the second display object.In some embodiments, the system 100 does this based at least in part ona determination that the portion of the first display object isco-located with the portion of the second display object. In certainembodiments, the system 100 can determine which display object is to bedisplayed in front of the other based at least on a priority level ofeach object. For example, the display object with the higher prioritycan be displayed in front of the other. In certain embodiments, thesystem causes the one or more displays to display one of the displayobjects in front of the other by moving the display object.

It will be understood that fewer, more, or different blocks can be usedas part of the routine 650. For example, in certain embodiments, thesystem 100 can determine and cause the one or more displays to displayperspective views of display objects.

In some embodiments, the routines 600, 650 can further include any oneor any combination of the embodiments described in the '274 Applicationand/or the embodiments described herein with references to FIGS. 4, 8A,and 8B. For example in some embodiments, the routines 600, 650 caninclude any one or any combination of: calculating a perspective view ina virtual 3D space of the at least one image based at least in part onthe emplacement information of the second medical device with respect tothe point-of-view location, causing the one or more displays to displaythe perspective view of the at least one image in the virtual 3D space,calculating a perspective view in the virtual 3D space of a virtualfirst medical device corresponding to the first medical device based atleast in part on the emplacement information of the first medical devicewith respect to the point-of-view location and/or calculating aperspective view in the virtual 3D space of a virtual second medicaldevice corresponding to the second medical device based at least in parton the emplacement information of the second medical device with respectto the point-of-view location, and causing the display device to displaya perspective view of the at least one of the virtual first medicaldevice and the virtual second medical device in the virtual 3D space.Any combination of the aforementioned embodiments can be used asdesired.

Transparency Levels

With returned reference to FIG. 5, FIG. 5 also illustrates usingdifferent transparency levels for a display object. Specifically, FIG. 5illustrates using different transparency levels for different portionsof the rendered image 506.

As mentioned previously, in some systems, some display objects aredisplayed with a high transparency setting so that display objectsbehind it can be seen. For example, in order to see the medical device504 when it is behind the rendered image 506, some systems would makethe rendered image 506 transparent or translucent (or have a hightransparency level). In such systems, the gridlines representing thebackground would be visible. However, by using a high transparencylevel, image intensity and contrast can be lost. As such by using a hightransparency level for the entire rendered image 506, some features(e.g., tumors, body tissue, blood vessels, etc.) in the rendered image506 may not be detected.

To alleviate this issue, the system can render those parts of therendered image 506 (or other display object) that do not have anotherdisplay object in front of or behind it at a low transparency level(e.g., opaque). For those parts of the rendered image 506 (or otherdisplay object) that have another display object behind it, the systemcan use a higher transparency level (more transparent). And for thoseparts of the rendered image 506 (or other display object) that have adisplay object in front of it, the system can render the other displayobject. As such, in some embodiments, the gridlines are not visiblethrough any part of the rendered image 506 (or other display object).

The system can render the different portions of the rendered image 506(or other display object) in a variety of ways. In some embodiments, thesystem determines for a particular location whether there is a portionof the rendered image 506 there and whether there is a portion ofanother display object behind the rendered image 506 (e.g., from theperspective of the point-of-view location). If the system determinesthat there is, the system can display the portion of the rendered image506 at that particular location at a first transparency level, and insome embodiments, can also display the other display object. If thesystem determines that there is a portion of the rendered image 506 atthe particular location and that there is not a portion of anotherdisplay object at the particular location, the system can display theportion of the rendered image at that particular location at a secondtransparency level that is lower than (e.g., more opaque) the firsttransparency level.

For example, with reference to FIG. 5, the virtual medical device 504 islocated in front of (e.g., from the perspective of the point-of-viewlocation) the rendered image 506 from its tip to the intersectionindicator 508. Similarly, the graphical image plane indicators 512 thatare located to the left and below the intersection indicator 508 are infront of the rendered image 506. From the intersection indicator 508 tothe top right corner of the rendered image 506, the virtual medicaldevice 504 and corresponding graphical plane indicators 512 are locatedbehind the rendered image 506.

Accordingly, for those locations on the rendered image 506 where theportions of other display objects (e.g., the medical device 504 and thegraphical image plane indicators 512) are located in front of therendered image 506 (e.g., portions the bottom left quadrant of therendered image 506), the system can cause the one or more displays todisplay the portions of the other display objects (and, in some cases,not display the rendered image 506). For those locations on the renderedimage 506 where the portions of the other display objects are locatedbehind the rendered image 506 (e.g., the medical device 504 and thegraphical image plane indicators 512 in the upper right quadrant of therendered image 506), the system can cause the one or more displays todisplay the portions of the rendered image 506 at a first transparencylevel overlaid in front of (or on top of) the portions of the otherdisplay objects. Finally, for those locations on the rendered image 506where there are no other display objects (e.g., bottom right quadrant ofthe rendered image 506, etc.), the system can cause the one or moredisplays to display the portions of the rendered image 506 at a secondtransparency level that is more opaque than the first transparencylevel.

With reference to FIG. 7, in some embodiments, the system can cause theone or more displays to display the portions of the rendered image atdifferent transparency levels by using multiple copies of the renderedimage. The first copy of the rendered image 702 can have a firsttransparency level (e.g., low transparency level and/or opaque) and thesecond copy 704 can have a second transparency level that is higher thanthe first transparency level.

In some embodiments, the system can cause the one or more displays todisplay the first copy of the rendered image 702. In certainembodiments, causing the one or more displays to display the first copy702, can result in the gridlines illustrated in FIG. 5 to not be visiblein the locations where the first copy 702 is displayed. The system canthen, in some cases, cause the one or more displays to display in frontof (or on top of) the first copy of the rendered image 702, the otherdisplay objects (e.g., virtual medical devices, image guidance cues,etc.) 706 that are to be located behind the rendered image on thedisplay (e.g., from the perspective of the point-of-view location).

Once the other display objects 706 that are to be located behind therendered image are placed in front of (or on top of) the first copy ofthe rendered image 702, the system can cause the one or more displays todisplay the second copy of the rendered image 704 in front of (or on topof) the first copy of the rendered image 702 and in front of (or on topof) the display objects 706 located behind the rendered image. Thesecond copy 704 can have a second transparency level that is higher thanthe first transparency level (e.g., more transparent). As such, thesecond copy 704 can be overlaid in front of (or on top of) the displayobjects 706 that are to be located behind the rendered image. In someembodiments, the second copy 704 is sufficiently transparent such thatthe gridlines illustrated in FIG. 5 would be visible if the second copy704 was displayed alone.

In addition, in some embodiments, the system can cause the one or moredisplays to display the display objects that are to be located in frontof the rendered image in front of (or on top of) the first and secondcopies of the rendered image 702, 704. In this manner, the portions ofthe rendered image that do not have another display object in front ofor behind it can be displayed more opaquely than the portions of therendered image that have one or more display objects 706 behind them.

FIG. 8A is a flow diagram illustrative of an embodiment of a routine 800implemented by the system 100 to display portions of a display object atdifferent transparency levels. One skilled in the relevant art willappreciate that the elements outlined for routine 800 can be implementedby one or more computing devices/components that are associated with thesystem 100, such as the position sensing unit 140, the image guidanceunit 130, surgical system 149, and/or imaging unit 150. Accordingly,routine 800 has been logically associated as being generally performedby the system 100. However, the following illustrative embodiment shouldnot be construed as limiting.

At block 802, the system 100 determines pose of a first medical devicebased at least in part on emplacement information of the first medicaldevice, as described in greater detail above with reference to block 602of FIG. 6. At block 804, the system 100 determines a pose of an imagedarea based at least in part on received emplacement information of asecond medical device, as described in greater detail above withreference to block 605 of FIG. 6. At block 806, the system 100 receivesimage data based at least on the emplacement information of the secondmedical device, as described in greater detail above with reference toblock 606 of FIG. 6.

At block 808, the system 100 determines whether at least a portion ofthe first medical device satisfies a location threshold. In someembodiments, at block 808, the system 100 determines that at least aportion of the first medical device satisfies the location threshold. Todetermine whether a portion of the first medical device satisfies alocation threshold, the system 100 can compare the coordinates of thefirst medical device with the coordinates of a particular locationwithin the imaged area. The particular location can refer to a varietyof locations within the imaged area and/or the imaged area as a whole.In some embodiments, the particular location can refer to a pixel thatcorresponds to the imaged area (e.g., a pixel within the imaged area).In certain embodiments, the pixel can correspond to a pixel on a displaythat displays an image of the imaged area, etc. In some embodiments, theparticular location can refer to multiple pixels, such as an array ofpixels, or other area within the imaged area, as desired.

Any coordinate system can be used to compare the coordinates of theportion of the first medical device with the particular location and/orto determine whether the portion of the first medical device is levelwith the particular location. For example, the coordinate system of thedisplay and/or the coordinate system of device in the system 100 that isused to determine the pose of the medical devices can be used, asdesired.

In some embodiments, the coordinate system of the display is used. Thecoordinate system of the display can be any pose as desired. In certainembodiments, the coordinates of the display are that the x-axis is thewidth of the display, the y-axis is the height of the display, and thez-axis is the depth (e.g., into and out of) the display. In suchembodiments, the system 100 can determine that the portion of the firstmedical device satisfies the location threshold and/or is level with theparticular location, based at least in part on the x and y coordinatesof the first medical device and the x and y coordinates of theparticular location. For example, if the x and y coordinates of thefirst medical device and the x and y coordinates of the particularlocation match (or satisfy a distance threshold), the system 100 candetermine that the portion of the first medical device satisfies thelocation threshold.

Although reference is made to the x and y coordinates, it will beunderstood that the coordinates used to determine whether the portion ofthe first medical device satisfies the location threshold and/or islevel with the particular location can be based at least in part on thecoordinate system used. For example, in some embodiments, the coordinatesystem used can include the x-axis as the depth (e.g.,forward/backward), the y-axis as lateral movement (e.g., side-to-side),and the z-axis as elevation (e.g., up/down). In such embodiments, thesystem 100 can determine that portion of the first medical devicesatisfies the location threshold if the y and z coordinates of the firstmedical device match (or satisfy a distance threshold) the y and zcoordinates of the particular location.

In certain embodiments, the system 100 can determine that the portion ofthe first medical device satisfies the location threshold and/or islevel with the particular location if the portion of the first medicaldevice and the particular location (or portion of the imagecorresponding to the particular location) are co-located when mapped toa 2D plane. In some embodiments, the 2D plane can be based at least inpart on the point-of-view location. For example, the 2D plane can beorthogonal to the point-of-view location. In certain embodiments, thesystem 100 can determine that the portion of the first medical devicesatisfies the location threshold (or corresponding virtual first medicaldevice) if the portion of the first medical device overlaps with theparticular location (or portion of the image corresponding to theparticular location) in a virtual image (e.g., one is directly in frontof or behind the other in the virtual image). In certain embodiments,the system 100 can determine that the portion of the first medicaldevice satisfies the location threshold if the portion of the firstmedical device and the particular location (or portion of the imagecorresponding to the particular location) map to the same location on adisplay, such as the same pixel or same array of pixels.

At block 810, based at least in part on a determination that the portionof the of the first medical device does not satisfy the locationthreshold, the system 100 can cause the one or more displays to displaya portion of the image corresponding to a particular location at a firsttransparency level. In some embodiments, the system 100 determines thatthe portion of the first medical device does not satisfy the locationthreshold and/or the portion of the first medical device is not levelwith the particular location based at least in part on a determinationthat the x and y coordinates (or other coordinates depending oncoordinate system used) of the portion of the first medical device donot match (or do not satisfy the distance threshold) the x and ycoordinates of the particular location mapped to the display (or portionof the image corresponding to the particular location). Similarly, thesystem 100 can determine that the portion of the first medical devicedoes not satisfy the location threshold based at least in part on thesystem determining that the portion of the first medical device and theparticular location (or portion of the image corresponding to theparticular location) are not co-located when mapped to a 2D plane, donot map to the same pixel and/or do not overlap in a virtual image.

The portion of the image corresponding to the particular location caninclude the portions of the image received. In some embodiments, theportions of the image can include one or more pixels or an array ofpixels in the image. In some embodiments, each pixel of the imagecorresponds to and/or can be mapped to a pixel in the imaged area.Accordingly, in some embodiments, the portion of the image thatcorresponds to the particular location can include the one or morepixels in the image that correspond to the one or more pixels in theimaged area that make up the particular location.

In some embodiments, the system 100 can display different locationsand/or pixels with different transparency levels (e.g., different alphatransparency). Accordingly, in some embodiments, the transparency levelcan correspond to how transparent, opaque, and/or bright a particularlocation is. The system 100 can use any number of different transparencylevels as desired. In certain embodiments, each transparency level isdifferent (e.g., more/less transparent) than the other transparencylevels. In some embodiments, the transparency level used can be based atleast in part on a priority level of the image and/or position of theimage.

At block 812, the system 100 can determine whether the portion of thefirst medical device satisfies a proximity threshold. In someembodiments, at block 812, the system 10 can determine the portion ofthe first medical device satisfies the proximity threshold. In certainembodiments, the system 10 determines the portion of the first medicaldevice satisfies the proximity threshold before, after and/orconcurrently with determining whether the portion of the first medicaldevice satisfies the location threshold.

The proximity threshold can be based at least in part on the proximityof the portion of the first medical device with respect to theparticular location and/or the point-of-view location. In someembodiments, the system 100 can determine that the portion of the firstmedical device satisfies the proximity threshold by determining that theportion of the first medical device is not proximal to a point-of-viewlocation with respect to the particular location (or portion of theimage corresponding to the particular location). In certain embodiments,the system 100 can determine that the portion of the first medicaldevice satisfies the proximity threshold by determining that the portionof the first medical device is not distal to a point-of-view locationwith respect to the particular location (or portion of the imagecorresponding to the particular location).

To determine whether the portion of the first medical device is proximalto a point-of-view location with respect to the particular location, thesystem 100 can compare the coordinates of the portion of the firstmedical device to the coordinates of the particular location (or portionof the image corresponding to the particular location) and/or comparethe coordinates of the portion of the virtual first medical devicecorresponding to the first medical device to the coordinates of theparticular location mapped to the display (or portion of the imagecorresponding to the particular location). Similar to the coordinatescompared for the location threshold described above, the coordinate thatis compared can be based at least in part on the coordinate system used(e.g., display coordinate system, system coordinate system, etc.).

In some embodiments, where the x and y coordinates are used to determinewhether the portion of the first medical device satisfies the locationthreshold, the z coordinate of the portion of the first medical deviceand the z coordinate of the particular location can be used to determinewhether the portion of the first medical device satisfies the proximitythreshold. Similarly, if the y and z coordinates are used to determinewhether the portion of the first medical device satisfies the locationthreshold, the x coordinate can be used to determine whether the portionof the first medical device satisfies the proximity threshold. Forexample, when using the x coordinate to determine whether the portion ofthe first medical device satisfies the proximity threshold, if the xcoordinate of the portion of the first medical device indicates that theportion of the first medical device is not proximal to the point-of-viewlocation with respect to the x coordinate of the particular location,the system 100 can determine that the portion of the first medicaldevice satisfies the proximity threshold. Similarly, if the x coordinateof the portion of the first medical device indicates that the portion ofthe first medical device is proximal to the point-of-view location withrespect to the imaged area, the system 100 can determine that theportion of the first medical device does not satisfy the proximitythreshold.

As described previously, the point-of-view location can refer to thelocation from which the virtual 3D space is viewed. For example, if thedisplay is considered a window into the virtual 3D space, thepoint-of-view location can be the location of the window with respect tothe object in the virtual 3D space. The system 100 can use thepoint-of-view location to draw the perspective views of the objects inthe 3D space.

At block 814, based at least in part on a determination that the portionof the first medical device satisfies the proximity threshold and thelocation threshold, the system 100 can cause the one or more displays todisplay the portion of the image corresponding to the particularlocation at a second transparency level. As mentioned previously, thesystem 100 can determine that the proximity threshold is satisfied bydetermining that the portion of the first medical device is proximal tothe point-of-view location with respect to the particular location ofthe imaged area. In addition, as mentioned previously, the system 100can determine that the portion of the first medical device satisfies thelocation threshold in a variety of ways.

In some embodiments, the second transparency level can correspond to atransparency level that is different from the first transparency level.In certain embodiments, the second transparency level is moretransparent (less opaque) than the first transparency level. In someembodiments, the second transparency level is less transparent (moreopaque) than the first transparency level.

It will be understood that fewer, more, or different blocks can be usedas part of the routine 800. For example, in some embodiments, the system100 can determine that the portion of the first medical device satisfiesthe location threshold and the proximity threshold, and display theportion of the image corresponding to the particular location at atransparency level that is different from a transparency level when thelocation threshold is not satisfied.

Furthermore, the order of the blocks can be changed as desired. Forexample, in some embodiments, the blocks 808 and 812 can be performed inparallel. In some embodiments one or more blocks can be repeated foreach location in the imaged area. For example, blocks 808-814 can berepeated for each unique location in the imaged area (or rendered imagearea). In addition, in any one or more of the blocks can be repeated foradditional medical devices. As a non-limiting example, the system 100can repeat blocks 802 and 808-814 for a third medical device, oradditional medical devices, etc.

In some embodiments, the method can further include mapping the imagedarea and/or image to a rendered image area on the one or more displays.For example, as part of processing and displaying the image, the system100 can map the imaged area and/or image to a rendered image area on thedisplay. As described previously, the rendered image area can be anypart of the display. In some embodiments, the size of the rendered imagearea can correspond to the size of the imaged area. In certainembodiments, the size of the rendered image area is smaller/larger than,or equal to, the size of the imaged area. As part of the mapping, thesystem 100 can map each location (e.g., each pixel or group of pixels)from the imaged area to corresponding locations in the rendered imagearea. For example, the top, right location in the imaged area can map tothe top, right location of the display image area, etc.

By mapping the imaged area to the rendered image area, the system 100can provide the image on the display in an area that corresponds to theimaged area. Furthermore, when the system 100 determines that aparticular location of the imaged area is to be displayed at a first orsecond transparency level, the system 100 can cause the one or moredisplays to display at a particular display location that corresponds tothe particular location, the portion of the image at the first or secondtransparency level. Similarly, the system 100 can cause the one or moredisplays to display at the particular display location, the portion ofthe virtual medical device as desired.

Furthermore, in some embodiments, the system 100 can cause the one ormore displays to display a portion of a virtual first medical devicecorresponding to the first medical device based at least in part on adetermination that the portion of the first medical device satisfies thelocation threshold. For example, if the portion of the first medicaldevice is level with the particular location (or otherwise satisfies thelocation threshold), the system 100 can cause the one or more displaysto display a portion of the virtual first medical at the particulardisplay location that corresponds to the particular location.

In addition, in certain embodiments, the system 100 can overlay theportion of the image corresponding to the particular location over (orin front of) the portion of the virtual first medical device at thesecond transparency level, based at least in part on the determinationthat the portion of the first medical device satisfies the proximitythreshold. For example, if the system 100 determines that the portion ofthe first medical device is behind the particular location, the system100 can display the virtual first medical device, and also display theportion of the image over the virtual first medical device. The imagecan be displayed more transparently than it otherwise would if the firstmedical device was not present at that particular location. In this way,the user can view the location of the virtual first medical device, aswell as the image. Furthermore, the user can ascertain from the displaythat the medical device is behind the imaged area.

In certain embodiments, when the portion of the first medical devicesatisfies the location threshold, but does not satisfy the proximitythreshold, the system 100 can cause the one or more displays to displaythe portion of the virtual first medical device. In such embodiments,the system 100 the system 100 can cause the one or more displays todisplay the portion of the virtual first medical device such that a userdoes not see the portion of the image corresponding to the particularlocation. For example, when the system 100 determines that the portionof the first medical device is co-located and/or located in front of theparticular location, the system 100 can display the portion of thevirtual first medical in front of, or instead of, the portion of theimage.

In some embodiments, the system 100 can overlay the different displayobjects on the display. In some embodiments, the system 100 can causethe one or more displays to display the overlaid display objects at arate so that a user is unable to discern any changes to the display. Forexample, in some embodiments, the system 100 can cause the one or moredisplays to display a portion of a first copy of the image correspondingto a particular location of the imaged area at the first transparencylevel. The system 100 can then determine whether the portion of thedisplay object satisfies a location threshold (e.g., is level with aportion of a rendered image). For the portions of the rendered imagethat are level with the display object (or the display object otherwisesatisfies the location threshold), the system 100 can cause the one ormore displays to display a portion of a display object. The portions ofthe display object can be displayed over, or in front of, the portionsof the first copy of the image.

In addition, the system 100 can determine whether the portion of thedisplay object satisfies the proximity threshold. For example, thesystem 100 can determine whether the display object is supposed to be infront of or behind the rendered image, from the perspective of thepoint-of-view location. Based at least in part on a determination thatthe portion of the display object satisfies the location threshold andthe proximity threshold, the system can cause the one or more displaysto display the portion of a second copy of the image corresponding tothe particular location at the second transparency level. For example,if the system 100 determines that the portion of the display object islevel with and behind (or co-located with) the portion of the renderedimage that corresponds to the particular location, the system 100 cancause the one or more displays to display the portion of the second copyof the image at a second transparency level (e.g., more transparent thanthe first transparency level), overlaid on top of (or in front of) theportion of the display object.

FIG. 8B is a flow diagram illustrative of an embodiment of a routine 850implemented by the system 100 to display portions of a display object atdifferent transparency levels. One skilled in the relevant art willappreciate that the elements outlined for routine 850 can be implementedby one or more computing devices/components that are associated with thesystem 100, such as the position sensing unit 140, the image guidanceunit 130, surgical system 149, and/or imaging unit 150. Accordingly,routine 850 has been logically associated as being generally performedby the system 100. However, the following illustrative embodiment shouldnot be construed as limiting.

At block 852, the system 100 determines a location of a first displayobject, as described in greater detail above with reference to block 652of FIG. 6B. At block 854, the system 100 determines a location of asecond display object, as described in greater detail above withreference to block 654 of FIG. 6B.

At block 856, the system 100 determines whether at least a portion ofthe first display object satisfies a location threshold. In someembodiments, at block 856, the system 100 determines that at least aportion of the first display object satisfies the location threshold. Todetermine whether a portion of the first display object satisfies alocation threshold, the system 100 can compare the coordinates of theportion of the first display object (e.g., medical device object, imageguidance cue, etc.) with the coordinates of a portion of the seconddisplay object (e.g., medical device object, image guidance cue, etc.).The portions can refer to a variety of locations within the first and/orsecond display objects as a whole, similar to the particular location ofthe imaged area, described in greater detail above. Any coordinatesystem can be used to compare the portions of the first and seconddisplay objects as described in greater detail above.

At block 858, based at least in part on a determination that the portionof the of the first display object does not satisfy the locationthreshold, the system 100 can cause the one or more displays to displaythe portion of the second display object at a first transparency level.

At block 860, the system 100 can determine whether the portion of thefirst display object satisfies a proximity threshold. In someembodiments, at block 860, the system 100 determines the portion of thefirst display object satisfies the proximity threshold. In certainembodiments, the system 10 determines the portion of the first displayobject satisfies the proximity threshold before, after and/orconcurrently with determining whether the portion of the first displayobject satisfies the location threshold.

The proximity threshold can be based at least in part on the proximityof the portion of the first display object with respect to the portionof the second display object and the point-of-view location. In someembodiments, the system 100 can determine that the portion of the firstdisplay object satisfies the proximity threshold by determining that theportion of the first display object is not proximal to a point-of-viewlocation with respect to the portion of the second display object. Incertain embodiments, the system 100 can determine that the portion ofthe first display object satisfies the proximity threshold bydetermining that the portion of the first display object is not distalto a point-of-view location with respect to the particular location (orportion of the image corresponding to the particular location).

To determine whether the portion of the first display object is proximalto a point-of-view location with respect to the particular location, thesystem 100 can compare the coordinates of the portion of the firstdisplay object to the coordinates of the portion of the second medicaldevice, as described in greater detail above.

At block 862, based at least in part on a determination that the portionof the first display object satisfies the proximity threshold and thelocation threshold, the system 100 can cause the one or more displays todisplay the portion of the second display object at a secondtransparency level. In some embodiments, the second transparency levelcan correspond to a transparency level that is different from the firsttransparency level. In certain embodiments, the second transparencylevel is more transparent (less opaque) than the first transparencylevel. In some embodiments, the second transparency level is lesstransparent more opaque) than the first transparency level.

It will be understood that fewer, more, or different blocks can be usedas part of the routine 850. For example, in some embodiments, the system100 can determine that the portion of the first display object satisfiesthe location threshold and the proximity threshold, and display theportion of the image corresponding to the particular location at atransparency level that is different from a transparency level when thelocation threshold is not satisfied.

In some embodiments, the routines 800, 850 can further include any oneor any combination of the embodiments described in the '274 Applicationand/or the embodiments described in FIGS. 4, 6A, and 6B. For example insome embodiments, the routines 800, 850 can include any one or anycombination of: calculating a perspective view in a virtual 3D space ofthe at least one image based at least in part on the emplacementinformation of the second medical device with respect to thepoint-of-view location, causing the one or more displays to display theperspective view of the at least one image in the virtual 3D space,calculating a perspective view in the virtual 3D space of a virtualfirst medical device corresponding to the first medical device based atleast in part on the emplacement information of the first medical devicewith respect to the point-of-view location and/or calculating aperspective view in the virtual 3D space of a virtual second medicaldevice corresponding to the second medical device based at least in parton the emplacement information of the second medical device with respectto the point-of-view location, and causing the display device to displaya perspective view of the at least one of the virtual first medicaldevice and the virtual second medical device in the virtual 3D space.Any combination of the aforementioned embodiments can be used asdesired.

EXAMPLE EMBODIMENTS

Various example embodiments of the disclosure can be described in viewof the following clauses:

-   -   Clause 1. A method, comprising:        -   determining a pose of a first medical device based at least            in part on received emplacement information of the first            medical device;        -   determining a pose of an imaged area based at least in part            on received emplacement information of a second medical            device;        -   receiving at least one image corresponding to the imaged            area based at least in part on the emplacement of the second            medical device;        -   determining whether a portion of the first medical device            satisfies a location threshold;        -   based at least in part on a determination that the portion            of the of the first medical device does not satisfy the            location threshold, causing the one or more displays to            display a portion of the image corresponding to a particular            location of the imaged area at a first transparency level;        -   determining whether the portion of the first medical device            satisfies a proximity threshold;        -   based at least in part on a determination that the portion            of the first medical device satisfies the location threshold            and the proximity threshold, causing the one or more            displays to display the portion of the image corresponding            to the particular location at a second transparency level.    -   Clause 2. The method of Clause 1, further comprising mapping the        imaged area to a rendered image area on the one or more        displays.    -   Clause 3. The method of Clause 1, further comprising mapping the        image to a rendered image area on the one or more displays.    -   Clause 4. The method of Clause 3, further comprising mapping the        portion of the image corresponding to the particular location to        a corresponding particular display location in the rendered        image area.    -   Clause 5. The method of Clause 4, further comprising causing the        one or more displays to display at the particular display        location the portion of the image at the first transparency        level.    -   Clause 6. The method of Clause 4, further comprising causing the        one or more displays to display at the particular display        location the portion of the image at the second transparency        level.    -   Clause 7. The method of Clause 1, wherein determining that the        portion of the first medical device satisfies the location        threshold comprises determining that the portion of the first        medical device is level with the particular location of the        imaged area.    -   Clause 8. The method of Clause 1, wherein determining that the        portion of the first medical device satisfies the location        threshold comprises determining that the x and y coordinates of        a portion of a virtual first medical device corresponding to the        portion of the first medical device match the x and y        coordinates of the particular location mapped to the one or more        displays.    -   Clause 9. The method of Clause 1, wherein determining that the        portion of the first medical device satisfies the location        threshold comprises determining that the y and z coordinates of        the portion of the first medical device match the y and z        coordinates of the particular location.    -   Clause 10. The method of Clause 1, wherein determining that the        portion of the first medical device satisfies the location        threshold comprises determining that the portion of the first        medical device and the particular location are co-located on a        2D plane.    -   Clause 11. The method of Clause 1, wherein determining that the        portion of the first medical device satisfies the location        threshold comprises determining that the portion of the first        medical device and the particular location are mapped to a same        pixel on the one or more displays.    -   Clause 12. The method of Clause 1, wherein determining that the        portion of the first medical device satisfies the location        threshold comprises determining that the portion of the first        medical device and the particular location overlap when mapped        to the one or more displays.    -   Clause 13. The method of Clause 1, wherein determining that the        portion of the first medical device satisfies the proximity        threshold comprises determining that the portion of the first        medical device is not proximal to a point-of-view location with        respect to the particular location.    -   Clause 14. The method of Clause 1, wherein the point-of-view        location comprises at least one of a location of a user, an        expected location of user, and a fixed point relative to the one        or more displays Clause 15. The method of Clause 14, wherein the        point-of-view location is different for each eye of a user.    -   Clause 16. The method of Clause 1, wherein the first        transparency level is more opaque than the second transparency        level.    -   Clause 17. The method of Clause 1, further comprising receiving        the at least one image from the second medical device.    -   Clause 18. The method of Clause 1, further comprising,        -   determining whether the portion of the first medical device            satisfies the location threshold for each unique location            within the imaged area;        -   determining whether the portion of the first medical device            satisfies the proximity threshold for each unique location            within the imaged area;        -   for each unique location in which the portion of the first            medical device does not satisfy the location threshold,            causing the one or more displays to display a portion of the            image corresponding to the unique location of the imaged            area at the first transparency level; and        -   for each unique location in which the portion of the first            medical device satisfies the location threshold and the            proximity threshold, causing the one or more displays to            display the portion of the image corresponding to the unique            location at the second transparency level.    -   Clause 19. The method of Clause 1, further comprising        calculating a perspective view in a virtual 3D space of the at        least one image based at least in part on the emplacement        information of the second medical device with respect to the        point-of-view location.    -   Clause 20. The method of Clause 19, further comprising causing        the one or more displays to display the perspective view of the        at least one image in the virtual 3D space.    -   Clause 21. The method of Clause 1, further comprising        calculating a perspective view in the virtual 3D space of at        least one of a virtual first medical device corresponding to the        first medical device based at least in part on the emplacement        information of the first medical device with respect to the        point-of-view location and a virtual second medical device        corresponding to the second medical device based at least in        part on the emplacement information of the second medical device        with respect to the point-of-view location.    -   Clause 22. The method of Clause 21, further comprising causing        the display device to display a perspective view of the at least        one of the virtual first medical device and the virtual second        medical device in the virtual 3D space.    -   Clause 23. A system comprising:        -   a computer system in communication with a display, the            computer system comprising a computer processor and a            non-transitory storage medium, wherein the computer system            is configured to:            -   determine a pose of a first medical device based at                least in part on emplacement information of the first                medical device received from a first pose sensor;            -   determine a pose of an imaged area based at least in                part on emplacement information of a second medical                device received from a second pose sensor;            -   receive at least one image corresponding to the imaged                area based at least in part on the emplacement of the                second medical device;            -   determine whether a portion of the first medical device                satisfies a location threshold;            -   determine whether the portion of the first medical                device satisfies a proximity threshold;            -   based at least in part on a determination that the                portion of the first medical device satisfies the                location threshold and the proximity threshold, cause                the one or more displays to display a portion of the                image corresponding to a particular location in the                imaged area at a first transparency level, wherein the                computer system causes the one or more displays to                display the portion of the image corresponding to the                particular location of the imaged area at a second                transparency level based at least in part on a                determination that the portion of the first medical                device does not satisfy the location threshold.    -   Clause 24. A method comprising:        -   determining a location of a first display object;        -   determining whether at least a portion of the first display            object satisfies a location threshold;        -   based at least in part on a determination that the portion            of the of the first display object does not satisfy the            location threshold, causing the one or more displays to            display the portion of the second display object at a first            transparency level;        -   determining whether the portion of the first display object            satisfies a proximity threshold; and        -   based at least in part on a determination that the portion            of the first display object satisfies the proximity            threshold and the location threshold, causing the one or            more displays to display the portion of the second display            object at a second transparency level.    -   Clause 25. A computer system in communication with a display,        the computer system comprising a computer processor and a        non-transitory storage medium, wherein the computer system is        configured to:        -   determine a location of a first display object based at            least in part on emplacement information of a first medical            device;        -   determine a location of a second display object based at            least in part on emplacement information of a second medical            device;        -   determine whether at least a portion of the first display            object is co-located with at least a portion of the second            display object;        -   based at least in part on a determination that the portion            of the first display object is co-located with the portion            of the second display object, cause the display to display            one of the portion of the first display object and the            portion of the second display object in front of the other            of the one of the portion of the first display object and            the portion of the second display object.    -   Clause 26. The system of Clause 25, wherein the computer system        is configured to determine whether the portion of the image        guidance cue from the one or more image guidance cues is        co-located with the portion of a medical display object by        comparing coordinates of the portion of the image guidance cue        with coordinates of the portion of the medical display object.    -   Clause 27. The system of Clause 26, wherein the computer system        is configured to adjust a coordinate of the one of the portion        of the image guidance cue and the portion of the display object        with respect to a point-of-view location, based at least in part        on a determination that the portion of the image guidance cue is        co-located with the portion of the medical display object.    -   Clause 28. The system of Clause 25, wherein the computer system        is configured to move the one of the portion of the image        guidance cue and the portion of the display object with respect        to a point-of-view location.    -   Clause 29. The system of Clause 25, wherein the computer system        is configured to move the one of the portion of the image        guidance cue and the portion of the display object forward with        respect to a point-of-view location.    -   Clause 30. The system of Clause 29, wherein the one of the        portion of the image guidance cue and the portion of the display        object that is moved forward is displayed at a transparency        level that is greater than the transparency level of the other        of the one of the portion of the image guidance cue and the        portion of the display object.    -   Clause 31. The system of Clause 25, wherein the image guidance        cue comprises at least one of an intersection indicator, a        trajectory indicator and a graphic plane indicator.    -   Clause 32. A method, comprising:        -   determining a location of a first medical device based at            least in part on received emplacement information of the            first medical device;        -   determining a location of an imaged area based at least in            part on received emplacement information of a second medical            device;        -   receiving at least one image corresponding to the imaged            area based at least in part on the emplacement of the second            medical device;        -   generating one or more image guidance cues based at least in            part on the determined location of the first medical device            and the determined location of the imaged area;        -   determining whether a portion of an image guidance cue from            the one or more image guidance cues is co-located with a            portion of a medical display object, wherein the medical            display object comprises at least one of a first virtual            medical device corresponding to the first virtual medical            device corresponding to the first medical device, a second            virtual medical device corresponding to the second medical            device medical device, and a rendered image corresponding to            the image;        -   based at least in part on a determination that the portion            of the image guidance cue is co-located with the portion of            the medical display object, causing the one or more displays            to display one of the portion of the image guidance cue and            the portion of the display object in front of the other of            the one of the portion of the image guidance cue and the            portion of the medical display object.    -   Clause 33. The method of Clause 32, wherein determining whether        the portion of the image guidance cue from the one or more image        guidance cues is co-located with the portion of a medical        display object, comprises comparing coordinates of the portion        of the image guidance cue with coordinates of the portion of the        medical display object.    -   Clause 34. The method of Clause 33, further comprising adjusting        a coordinate of the one of the portion of the image guidance cue        and the portion of the display object with respect to a        point-of-view location, based at least in part on a        determination that the portion of the image guidance cue is        co-located with the portion of the medical display object.    -   Clause 35. The method of Clause 32, further comprising moving        the one of the portion of the image guidance cue and the portion        of the display object with respect to a point-of-view location.    -   Clause 36. The method of Clause 32, further comprising moving        the one of the portion of the image guidance cue and the portion        of the display object forward with respect to a point-of-view        location.    -   Clause 37. The method of Clause 36, wherein the one of the        portion of the image guidance cue and the portion of the display        object that is moved forward is displayed at a transparency        level that is greater than the transparency level of the other        of the one of the portion of the image guidance cue and the        portion of the display object.    -   Clause 38. The method of Clause 32, wherein the image guidance        cue comprises at least one of an intersection indicator, a        trajectory indicator and a graphic plane indicator.    -   Clause 39. A method, comprising:        -   receiving a configuration command;        -   determining a pose of a medical device with respect to a            reference location based at least in part on received            emplacement information of the medical device;        -   determining a point-of-view location based at least in part            on the determined pose of the medical device with respect to            the reference location; and        -   determining a perspective view of a virtual medical device            corresponding to the medical device based at least in part            on a pose of the medical device with respect to the            point-of-view location, and        -   causing one or more displays to display the perspective view            of the virtual medical device in a virtual 3D space.    -   Clause 40. The method of Clause 39, further comprising        determining a pose of one or more displays with respect to the        reference location.    -   Clause 41. The method of Clause 40, further comprising        determining the point-of-view location based at least in part on        the determined pose of the one or more displays.    -   Clause 42. The method of Clause 39, wherein the reference        location comprises at least one of a position sensing unit, a        portion of the position sensing unit, a coordinate system of the        position sensing unit, and a geographic direction.    -   Clause 43. The method of Clause 39, wherein the configuration        command is a first configuration command, the pose of the        medical device is a first pose of the medical device, the        point-of-view location is a first point-of-view location, the        one or more displays is a first set of one or more displays, the        virtual 3D space is a first virtual 3D space, and the received        emplacement information of the medical device comprises        emplacement information received at a first time, the method        further comprising:        -   determining a second pose of the medical device with respect            to the reference location based at least in part on            emplacement information of the medical device received at a            second time;        -   determining a second point-of-view location based at least            in part on the determined second pose of the medical device            with respect to the reference location; and        -   determining a second perspective view of the virtual medical            device based at least in part on an pose of the medical            device with respect to the second point-of-view location,            and causing a second set one or more displays to display the            second perspective view of the virtual medical device in a            second virtual 3D space.    -   Clause 44. The method of Clause 39, wherein the medical device        is a first medical device, the method further comprising        determining a location of an imaged area based at least in part        on received emplacement information of a second medical device.    -   Clause 45. The method of Clause 44, further comprising receiving        at least one image corresponding to the imaged area based at        least in part on the emplacement of the second medical device.    -   Clause 46. The method of Clause 45, further comprising        calculating a perspective view in a virtual 3D space of the at        least one image based at least in part on the emplacement        information of the second medical device with respect to the        point-of-view location.    -   Clause 47. The method of Clause 46, further comprising causing        the one or more displays to display the perspective view of the        at least one image in the virtual 3D space.    -   Clause 48. The method of Clause 44, further comprising        calculating a perspective view in the virtual 3D space of a        virtual second medical device corresponding to the second        medical device based at least in part on the emplacement        information of the second medical device with respect to the        point-of-view location.    -   Clause 49. The method of Clause 48, further comprising causing        the display device to display a perspective view of the virtual        second medical device in the virtual 3D space.    -   Clause 50. A computer system in communication with a display,        the computer system comprising a computer processor and a        non-transitory storage medium, wherein the computer system is        configured to:        -   receiving a configuration command;        -   determining a pose of a medical device with respect to a            reference location based at least in part on received            emplacement information of the medical device;        -   determining a point-of-view location based at least in part            on the determined pose of the medical device with respect to            the reference location; and        -   determining a perspective view of a virtual medical device            corresponding to the medical device based at least in part            on a pose of the medical device with respect to the            point-of-view location, and        -   causing one or more displays to display the perspective view            of the virtual medical device in a virtual 3D space.    -   Clause 51. The system of Clause 50, wherein the computer system        is further configured to determine a pose of one or more        displays with respect to the reference location.    -   Clause 52. The system of Clause 51, wherein the computer system        is further configured to determine the point-of-view location        based at least in part on the determined pose of the one or more        displays.    -   Clause 53. The system of Clause 50, wherein the reference        location comprises at least one of a position sensing unit, a        portion of the position sensing unit, a coordinate system of the        position sensing unit, and a geographic direction.    -   Clause 54. The system of Clause 50, wherein the configuration        command is a first configuration command, the pose of the        medical device is a first pose of the medical device, the        point-of-view location is a first point-of-view location, the        one or more displays is a first set of one or more displays, the        virtual 3D space is a first virtual 3D space, and the received        emplacement information of the medical device comprises        emplacement information received at a first time, and the        computer system is further configured to:        -   determine a second pose of the medical device with respect            to the reference location based at least in part on            emplacement information of the medical device received at a            second time;        -   determine a second point-of-view location based at least in            part on the determined second pose of the medical device            with respect to the reference location; and        -   determine a second perspective view of the virtual medical            device based at least in part on an pose of the medical            device with respect to the second point-of-view location,            and        -   cause a second set one or more displays to display the            second perspective view of the virtual medical device in a            second virtual 3D space.    -   Clause 55. The system of Clause 50, wherein the medical device        is a first medical device, and wherein the computer system is        further configured to determine a location of an imaged area        based at least in part on received emplacement information of a        second medical device.    -   Clause 56. The system of Clause 55, wherein the computer system        is further configured to receive at least one image        corresponding to the imaged area based at least in part on the        emplacement of the second medical device.    -   Clause 57. The system of Clause 56, wherein the computer system        is further configured to calculate a perspective view in a        virtual 3D space of the at least one image based at least in        part on the emplacement information of the second medical device        with respect to the point-of-view location.    -   Clause 58. The system of Clause 57, wherein the computer system        is further configured to cause the one or more displays to        display the perspective view of the at least one image in the        virtual 3D space.    -   Clause 59. The system of Clause 55, wherein the computer system        is further configured to calculate a perspective view in the        virtual 3D space of a virtual second medical device        corresponding to the second medical device based at least in        part on the emplacement information of the second medical device        with respect to the point-of-view location.    -   Clause 60. The system of Clause 59, wherein the computer system        is further configured to cause the display device to display a        perspective view of the virtual second medical device in the        virtual 3D space.

Terminology

Those having skill in the art will further appreciate that the variousillustrative logical blocks, modules, circuits, and process stepsdescribed in connection with the implementations disclosed herein can beimplemented as electronic hardware, computer software, or combinationsof both. To clearly illustrate this interchangeability of hardware andsoftware, various illustrative components, blocks, modules, circuits,and steps have been described above generally in terms of theirfunctionality. Whether such functionality is implemented as hardware orsoftware depends upon the particular application and design constraintsimposed on the overall system. Skilled artisans can implement thedescribed functionality in varying ways for each particular application,but such implementation decisions should not be interpreted as causing adeparture from the scope of the present invention. One skilled in theart will recognize that a portion, or a part, can comprise somethingless than, or equal to, a whole. For example, a portion of a collectionof pixels can refer to a sub-collection of those pixels.

The various illustrative logical blocks, modules, and circuits describedin connection with the implementations disclosed herein can beimplemented or performed with a general purpose processor, a digitalsignal processor (DSP), an application specific integrated circuit(ASIC), a field programmable gate array (FPGA) or other programmablelogic device, discrete gate or transistor logic, discrete hardwarecomponents, or any combination thereof designed to perform the functionsdescribed herein. A general purpose processor can be a microprocessor,but in the alternative, the processor can be any conventional processor,controller, microcontroller, or state machine. A processor can also beimplemented as a combination of computing devices, e.g., a combinationof a DSP and a microprocessor, a plurality of microprocessors, one ormore microprocessors in conjunction with a DSP core, or any other suchconfiguration.

The steps of a method or process described in connection with theimplementations disclosed herein can be embodied directly in hardware,in a software module executed by a processor, or in a combination of thetwo. A software module can reside in RAM memory, flash memory, ROMmemory, EPROM memory, EEPROM memory, registers, hard disk, a removabledisk, a CD-ROM, or any other form of non-transitory storage medium knownin the art. An exemplary computer-readable storage medium is coupled tothe processor such the processor can read information from, and writeinformation to, the computer-readable storage medium. In thealternative, the storage medium can be integral to the processor. Theprocessor and the storage medium can reside in an ASIC. The ASIC canreside in a user terminal, camera, or other device. In the alternative,the processor and the storage medium can reside as discrete componentsin a user terminal, camera, or other device.

Headings are included herein for reference and to aid in locatingvarious sections. These headings are not intended to limit the scope ofthe concepts described with respect thereto. Such concepts can haveapplicability throughout the entire specification.

The previous description of the disclosed implementations is provided toenable any person skilled in the art to make or use the presentinvention. Various modifications to these implementations will bereadily apparent to those skilled in the art, and the generic principlesdefined herein can be applied to other implementations without departingfrom the spirit or scope of the invention. Furthermore, althoughdescribed above with reference to medical devices and procedures, itwill be understood that the embodiments described herein can be appliedto other systems in which objects are tracked and virtualrepresentations are displayed on a display and/or systems in whichmultiple objects are displayed on a display within a virtual space, suchas within a virtual 3D space. Thus, the present invention is notintended to be limited to the implementations shown herein but is to beaccorded the widest scope consistent with the principles and novelfeatures disclosed herein.

1. A method, comprising: determining a pose of a first medical devicebased at least in part on received emplacement information of the firstmedical device; determining a pose of an imaged area based at least inpart on received emplacement information of a second medical device;receiving at least one image corresponding to the imaged area based atleast in part on the emplacement of the second medical device;determining whether a portion of the first medical device satisfies alocation threshold; based at least in part on a determination that theportion of the of the first medical device does not satisfy the locationthreshold, causing the one or more displays to display a portion of theimage corresponding to a particular location of the imaged area at afirst transparency level; determining whether the portion of the firstmedical device satisfies a proximity threshold; based at least in parton a determination that the portion of the first medical devicesatisfies the location threshold and the proximity threshold, causingthe one or more displays to display the portion of the imagecorresponding to the particular location at a second transparency level.2. The method of claim 1, further comprising mapping the imaged area toa rendered image area on the one or more displays.
 3. The method ofclaim 1, further comprising mapping the image to a rendered image areaon the one or more displays.
 4. The method of claim 3, furthercomprising mapping the portion of the image corresponding to theparticular location to a corresponding particular display location inthe rendered image area.
 5. The method of claim 4, further comprisingcausing the one or more displays to display at the particular displaylocation the portion of the image at the first transparency level. 6.The method of claim 4, further comprising causing the one or moredisplays to display at the particular display location the portion ofthe image at the second transparency level.
 7. The method of claim 1,wherein determining that the portion of the first medical devicesatisfies the location threshold comprises determining that the portionof the first medical device is level with the particular location of theimaged area.
 8. The method of claim 1, wherein determining that theportion of the first medical device satisfies the location thresholdcomprises determining that the x and y coordinates of a portion of avirtual first medical device corresponding to the portion of the firstmedical device match the x and y coordinates of the particular locationmapped to the one or more displays.
 9. The method of claim 1, whereindetermining that the portion of the first medical device satisfies thelocation threshold comprises determining that the y and z coordinates ofthe portion of the first medical device match the y and z coordinates ofthe particular location.
 10. The method of claim 1, wherein determiningthat the portion of the first medical device satisfies the locationthreshold comprises determining that the portion of the first medicaldevice and the particular location are co-located on a 2D plane.
 11. Themethod of claim 1, wherein determining that the portion of the firstmedical device satisfies the location threshold comprises determiningthat the portion of the first medical device and the particular locationare mapped to a same pixel on the one or more displays.
 12. The methodof claim 1, wherein determining that the portion of the first medicaldevice satisfies the location threshold comprises determining that theportion of the first medical device and the particular location overlapwhen mapped to the one or more displays.
 13. The method of claim 1,wherein determining that the portion of the first medical devicesatisfies the proximity threshold comprises determining that the portionof the first medical device is not proximal to a point-of-view locationwith respect to the particular location.
 14. The method of claim 1,wherein the point-of-view location comprises at least one of a locationof a user, an expected location of user, and a fixed point relative tothe one or more displays
 15. The method of claim 14, wherein thepoint-of-view location is different for each eye of a user.
 16. Themethod of claim 1, wherein the first transparency level is more opaquethan the second transparency level.
 17. The method of claim 1, furthercomprising receiving the at least one image from the second medicaldevice.
 18. The method of claim 1, further comprising, determiningwhether the portion of the first medical device satisfies the locationthreshold for each unique location within the imaged area; determiningwhether the portion of the first medical device satisfies the proximitythreshold for each unique location within the imaged area; for eachunique location in which the portion of the first medical device doesnot satisfy the location threshold, causing the one or more displays todisplay a portion of the image corresponding to the unique location ofthe imaged area at the first transparency level; and for each uniquelocation in which the portion of the first medical device satisfies thelocation threshold and the proximity threshold, causing the one or moredisplays to display the portion of the image corresponding to the uniquelocation at the second transparency level.
 19. (canceled)
 20. (canceled)21. (canceled)
 22. (canceled)
 23. A system comprising: a computer systemin communication with a display, the computer system comprising acomputer processor and a non-transitory storage medium, wherein thecomputer system is configured to: determine a pose of a first medicaldevice based at least in part on emplacement information of the firstmedical device received from a first pose sensor; determine a pose of animaged area based at least in part on emplacement information of asecond medical device received from a second pose sensor; receive atleast one image corresponding to the imaged area based at least in parton the emplacement of the second medical device; determine whether aportion of the first medical device satisfies a location threshold;determine whether the portion of the first medical device satisfies aproximity threshold; based at least in part on a determination that theportion of the first medical device satisfies the location threshold andthe proximity threshold, cause the one or more displays to display aportion of the image corresponding to a particular location in theimaged area at a first transparency level, wherein the computer systemcauses the one or more displays to display the portion of the imagecorresponding to the particular location of the imaged area at a secondtransparency level based at least in part on a determination that theportion of the first medical device does not satisfy the locationthreshold.
 24. A method comprising: determining a location of a firstdisplay object; determining whether at least a portion of the firstdisplay object satisfies a location threshold; based at least in part ona determination that the portion of the of the first display object doesnot satisfy the location threshold, causing the one or more displays todisplay the portion of the second display object at a first transparencylevel; determining whether the portion of the first display objectsatisfies a proximity threshold; and based at least in part on adetermination that the portion of the first display object satisfies theproximity threshold and the location threshold, causing the one or moredisplays to display the portion of the second display object at a secondtransparency level.